The Science of Hair Growth: Tools for Prevention and Regrowth

# The Science of Healthy Hair, Hair Loss and How to Regrow Hair | Huberman Lab Podcast
# https://www.youtube.com/watch/6ZrlsVx85ek

00:00:00.200 ANDREW HUBERMAN: Welcome to theHuberman Lab podcast,
00:00:02.190 where we discuss science and science-based tools for everyday life.
00:00:06.050 [MUSIC PLAYING]
00:00:09.080 I’m Andrew Huberman,and I’m a professor of neurobiology
00:00:11.750 and ophthalmologyat Stanford School of Medicine.
00:00:14.530 Today, we are discussing hair.
00:00:16.670 Hair is a topic that occupiesthe minds of many people.
00:00:20.330 There are people that are losing their
00:00:22.510 hair and want to halt orreverse that loss of hair.
00:00:26.840 Today, we will talk about all the ways
00:00:28.580 that science has taught us we canslow or even reverse hair loss.
00:00:32.950 I confess that researching today’s topic
00:00:35.110 was a particular joy for me not becauseI’m obsessed with hair,
00:00:38.820 mine or the hair of others,but because hair turns out to be
00:00:42.390 fascinating from the perspectiveof cellular biology and stem cells,
00:00:46.950 which is a topic that I’ve long beeninterested in and that for much
00:00:50.870 of my career I focused on inthe context of development.
00:00:54.400 When your brain and your nervous systemdevelop, it develops from a small batch
00:00:58.310 of cells that turnsinto many trillions of cells.
00:01:01.330 It does that by cell replication,something that we call the cell cycle.
00:01:06.160 We’ll talk a little bit aboutthis and so-called mitosis today.
00:01:09.440 I promise not to get into too much detail.
00:01:11.470 But what makes hair so very interestingfrom a biological standpoint is that every
00:01:16.870 hair, every single individual strandof hair has its own little stem cell
00:01:21.910 niche, meaning its own little pocket downthere in the follicle in which specific
00:01:26.070 stem cells give rise to those hairsfor different durations of time,
00:01:31.110 depending on the hair,where it is on your body, et cetera.
00:01:34.290 For instance, the hairs on your head will
00:01:37.390 undergo ongoing growthfor 4-6 or even 8 years.
00:01:42.690 Were you to not cut your hair,it would continue to grow.
00:01:46.110 One single hair would continue to grow.
00:01:48.430 I guess we could say all the hairs willcontinue to grow for up to 8 years.
00:01:53.050 That is very different from, for instance,your eyebrows, which have a much shorter
00:01:58.430 period of hair growth lastingon the order of months.
00:02:01.240 That’s why you don’t see people witheyebrows that extend down to their waist.
00:02:04.910 But you can see people with hair on their
00:02:07.390 head that extends down to theirwaist if they don’t cut it.
00:02:10.759 Now, that discrepancy illustrates for us
00:02:13.150 just how incredible hair folliclesand the stem cells that reside within
00:02:17.750 hairs are and their enormous potentialto give rise to these things that we call
00:02:21.950 hairs, which are simply proteinsof varying length.
00:02:26.040 Today, we are going to address what
00:02:27.670 determines the length of a hair or ratherwhat determines how long a hair continues
00:02:33.310 to grow before it ceases growingand eventually falls out.
00:02:36.520 We’re going to talk about what regulatesthose stem cells,
00:02:39.030 what allows them to continue to producehair or cease producing hair.
00:02:43.510 As we do that,
00:02:44.870 you will learn all the biology in clear,simple terms,
00:02:48.280 regardless of your background,that will really set the stage
00:02:51.030 for understanding what we’ll also talkabout, which is how to slow hair loss or
00:02:57.390 halt hair loss entirely oreven reverse hair loss.
00:03:01.240 We will talk about hormone -relatedhair loss in both men and women.
00:03:04.280 We will talk about some of the mechanical
00:03:06.230 and stress -relatedinfluences on hair loss.
00:03:08.640 We will talk about the chemical
00:03:10.550 and mechanical approaches to haltingand reversing hair loss,
00:03:13.950 everything from minoxidil todutasteride to ketoconazole
00:03:19.190 to microneedling to thyroid,estrogen, IGF-1 pathways.
00:03:24.390 Again, all made very clear regardless
00:03:26.550 of whether or not you havea background in biology or not.
00:03:30.360 I will also dispel some of the commonmyths about balding and hair replacement.
00:03:34.230 If you’ve heard, for instance,that you inherit your patterns of balding
00:03:37.950 from your mother’s father,that is not true.
00:03:42.030 Although it is true that you do inheritcertain genes that influence whether or
00:03:46.670 not you have a predisposition to baldingin particular parts of your head,
00:03:51.000 and believe it or not,even in particular parts of your body.
00:03:53.350 But it is not the case that you can simply
00:03:55.550 find a photo of your mother’s father, say,age 50, or age 60 or 75,
00:04:01.480 and determine whether or not you’ll havethe exact same pattern of hair loss.
00:04:04.530 That’s a myth that I’d liketo dispel right here and now.
00:04:07.760 I will dispel some of the other myths
00:04:09.030 about hair loss, hair replacement,and hair regrowth as well.
00:04:13.480 Before we begin, I’d like to emphasize
00:04:15.320 that this podcast is separate from myteaching and research roles at Stanford.
00:04:18.709 It is, however,
00:04:19.519 part of my desire and effort to bring zerocost to consumer information about science
00:04:23.440 and science-related toolsto the general public.
00:04:25.680 In keeping with that theme, I’d liketo thank the sponsors of today’s podcast.
00:04:29.530 Our first sponsor is Helix Sleep.
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00:05:38.350 Today’s episode is also broughtto us by HVMN ketone-IQ.
00:05:42.360 Ketone-IQ is a ketone supplementthat increases blood ketones.
00:05:46.520 I want to be very clear that I, like mostpeople have heard of the ketogenic diet,
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00:08:04.470 Okay, let’s talk about hair.
00:08:06.130 In researching this episode by talking
00:08:08.290 to experts in the biology of hair,and the stem cells that exist in all of us
00:08:13.030 that give rise to our hair growth,and the pigmentation in our hair,
00:08:17.270 and in talking to experts who understandhow to halt and even reverse hair loss,
00:08:22.860 that there is a tremendouslyinteresting biology surrounding hair.
00:08:27.030 But there’s also an incrediblepsychology around hair.
00:08:30.920 In fact, most people who experience even
00:08:34.030 marginal hair loss undergopretty severe anxiety.
00:08:37.520 Now, I confess this is notsomething I can relate to.
00:08:39.909 I am losing my hair in certain places.
00:08:42.169 I’m 47 years old.
00:08:43.200 I’ve got a couple of patches up frontwhere there’s very minimal hair.
00:08:46.630 I think that, as we’ll later learn in this
00:08:49.060 episode, reflects a higher density of DHT,dihydrotestosterone, receptors
00:08:54.360 at that particular location asopposed to elsewhere in my scalp.
00:08:57.300 But keeping my hair is not somethingthat I’ve fretted about much of my life.
00:09:01.130 Yet as I was researching this episode,I remembered an anecdote from my childhood
00:09:05.270 where my father told me,and I think it was because I was stressing
00:09:10.820 about something,I was trying to get to sleep, and he said,
00:09:14.060 “Don’t stress . Calmdown.” And here’s why.
00:09:17.530 If you stress too much,it can actually make your hair fall out.
00:09:21.790 In fact, I have a cousin who lay down onenight stressed,
00:09:25.510 and woke up the next morning , andall of his hair was on his pillow.
00:09:29.810 I’ll never forget that story.
00:09:31.630 I think he was tryingto get me to stress less.
00:09:34.190 I don’t know if that storymade me stress less or not.
00:09:37.410 But in any event, I don’tknow that that story is true.
00:09:40.400 I’m not going to challengethe authenticity of that story.
00:09:42.820 I didn’t have a chance to reach outto my father and ask him to verify or not.
00:09:47.190 But as we will soon learn,
00:09:48.790 it is true that our psychologicalwell-being can impact both the coloration
00:09:55.030 ,, or lack thereof and thegrowth rates of our hair.
00:09:58.150 That’s a real thing.
00:10:00.010 The reverse is also true,
00:10:01.430 which is that as hair starts to thin, orfall out, or change color,
00:10:06.550 many people expect intenseanxiety or even depression.
00:10:10.230 This was not somethingI was really aware of.
00:10:12.920 Perhaps that’s just because I’ve alwayskept my hair pretty short anyway.
00:10:15.400 I always assumed that if my hair started
00:10:16.680 to really fall out,I would just shaved my head.
00:10:18.350 But that’s me, and that’snot most people out there.
00:10:21.750 I think most people wouldloathe to lose their hair.
00:10:25.290 In fact, given the enormous number,
00:10:28.630 probably up in the high billionsof dollars and euros and other currency,
00:10:34.630 of course, that people invest in tryingto halt or reverse their hair loss,
00:10:38.670 it’s clear that hair isvery important to people.
00:10:41.250 What we know is that by age 50,approximately 50% of all men and women
00:10:46.670 will have experienced significant enoughhair loss that they start to notice it.
00:10:51.270 And a large percentage,
00:10:53.270 up to 85% of those people will experiencesome anxiety that leads them to go out
00:10:59.750 and try and either halt orreverse that hair loss.
00:11:02.430 Now, why at age 50?
00:11:04.830 Well, an important point arises from that,which is that the hair loss is not
00:11:09.110 occurring between the 49thand 50th birthday.
00:11:11.610 Hair loss is ongoingfrom about age 30 to age 50.
00:11:16.910 It’s only by age 50, however,
00:11:18.830 that about 50% of people out therestart to notice that hair loss.
00:11:23.690 This is typically because
00:11:25.080 they’ll be in a bathroom or lookingin a mirror and the lighting will be
00:11:29.030 bright enough that it permeatesthe outer boundary of their hair.
00:11:32.920 They’ll notice that their hair isthinning in a particular location.
00:11:35.630 That’s usually how this thing happens.
00:11:37.890 Again, our psychological states can impactour patterns of hair growth or loss
00:11:43.630 and of course, patterns of hair growth,but more typically,
00:11:46.670 hair loss and hair graying canreally impact psychological states.
00:11:50.130 This is a subject that peopletake intense interest in.
00:11:53.720 Today, we’re going to talk about how hair
00:11:55.750 normally grows, why it grows at the rate, and for the duration that it happens to.
00:12:02.490 Then as we talk about ways to intervenewith that hair loss,
00:12:05.520 those biological mechanisms will come upbecause they really provide a nice
00:12:08.990 framework for explaining why certaintreatments work more or less well or why
00:12:14.560 certain treatments might have certain sideeffects or total lack of side effects.
00:12:18.550 It will also highlight a really key theme
00:12:20.760 that will come up several times in today’spodcast, which is that there are both
00:12:24.310 mechanical and chemical approachesto slowing and reversing hair loss.
00:12:30.330 Mechanical approaches would be things as
00:12:32.750 simple as massaging the scalp,but mechanical changes to the scalp can
00:12:37.670 cause either hair loss orfacilitate hair growth.
00:12:41.000 This is why things like microneedling are
00:12:43.070 so prominent in the contextof trying to reverse hair loss.
00:12:46.240 But again, there are also chemical
00:12:47.910 approaches to trying to haltor reverse hair loss.
00:12:51.290 This relates to the fact that the hairgrowth itself is strongly regulated
00:12:56.030 by hormones such as estrogen,thyroid hormone,
00:12:59.550 insulin-like growth factor,and that other hormones, in particular
00:13:03.710 the androgens,so things like testosterone,
00:13:06.580 but mainly it’s derivatives likedihydrotestosterone are very much involved
00:13:11.750 in setting the stage for hair growthby controlling how big or small that pool
00:13:16.910 of stem cells that gives riseto hair growth is.
00:13:20.120 If any of the terms I just use are
00:13:21.600 confusing to you, don’t worry, I willmake all of those very clear in a moment.
00:13:25.270 It’s actually all prettystraightforward and simple.
00:13:28.530 I’d like to just start by talking about
00:13:30.950 what hair is, how it grows, why it stopsgrowing, and why hair normally falls out.
00:13:37.710 Let’s talk about the biology of hair.
00:13:39.770 In doing so, I also wantto talk about stem cells.
00:13:42.400 Now, keep in mind that when you hear
00:13:43.710 the word stem cells, you probably,like most people, think about the sorts
00:13:47.840 of cells that people are getting injectedinto their face to get rid of wrinkles,
00:13:51.360 or give them new skin,or to give them more hair if it’s
00:13:53.710 injected in the scalp, or into a jointto repair a joint or a muscle.
00:13:58.890 Those stem cells are what wecall exogenous stem cells.
00:14:02.150 Exogenous, meaning from outside the body.
00:14:06.120 The stem cells that we’re going to talkabout today are so-called endogenous stem
00:14:09.510 cell, cells that we all makethat can give rise to other cells.
00:14:12.920 That’s really the definitionof a stem cell.
00:14:14.970 Stem cells are present in all of usfrom the very beginning of life.
00:14:18.530 When sperm meets egg, that cell,
00:14:21.800 which we think of as the egg,starts to duplicate,
00:14:24.230 it incorporates the DNA from the spermand the egg, of course,
00:14:27.440 starts to duplicate,and then those cells give rise to more
00:14:29.960 cells and more cells and the abilityof all those cells to replicate and create
00:14:33.110 more cells are because thosecells really are stem cells.
00:14:36.370 Now, at some point we are a completedbody plan, as the biologists say.
00:14:42.010 We end up with a brain, and a spinal cord,and limbs, and fingers, and livers,
00:14:47.360 and guts, and all the things that we needin order to be a functioning human being.
00:14:51.280 Even though we’re a baby at that time,we haven’t grown up,
00:14:53.470 we have all the bits that we’regoing to have for our entire life.
00:14:57.210 At that point, many of the stemcell populations disappear.
00:15:01.550 For instance, past puberty,
00:15:04.410 and probably earlier, you don’tget many more new brain cells.
00:15:08.320 You get a few, but you don’t get many morenew brain cells because the brain doesn’t
00:15:11.990 have many stem cell populations,whereas other organs in your body maintain
00:15:16.670 little pockets of stem cells,or in some cases, many stem cells that can
00:15:21.230 give rise to more and moreof that tissue across the lifespan.
00:15:24.810 Hair is one such tissue.
00:15:27.130 If we take a look at hair,what we find is that, indeed,
00:15:30.280 there are these things that we call hairs,but there are also stem cells,
00:15:33.750 and those stem cells are actually whatgive rise to the hairs that we see
00:15:38.110 on the head of our scalp or that wesee on the surface of our body.
00:15:42.810 Right off the bat,
00:15:43.830 you should know that every single hairthat you have is there because you have
00:15:48.150 a stem cell population that is givingrise to that particular hair.
00:15:53.080 Let’s take a step back, or rather,
00:15:55.270 I should say, let’s zoom in on one hairand the stem cell population that gives
00:16:00.480 rise to that hair, because in doing so,you’re going to learn all the different
00:16:04.430 components that you can tap into if yourgoal is to halt the loss of hairs or
00:16:10.230 to replace hairs that havealready been lost.
00:16:13.650 If we were to just zoom in at the level
00:16:16.110 of one hair, what you would find isthat that hair has what typically is
00:16:21.030 called a hair root, so that’sthe portion below the skin.
00:16:24.280 When we say below the skin,
00:16:25.310 it means that it dives down into a narrowtrench, which is in the so-called
00:16:30.750 epidermis, which is thisouter layer of skin.
00:16:33.270 It also has a shaft.
00:16:35.070 The shaft is the partthat grows out above the skin.
00:16:38.490 What you see on somebody’s heador you see on their arm,
00:16:41.600 or when you see an eyebrow,you’re seeing the shaft of the hair.
00:16:44.630 The root, of course, goes below the skin.
00:16:47.760 What most people don’t realize, however,is that down at the base of the root,
00:16:51.270 there’s actually a littlecave, a little pocket.
00:16:54.560 If you were to look at this,it would look like a little bulb,
00:16:56.990 a little round area with a bunchof stuff in it right below the root.
00:17:02.010 Within that little cave,there are stem cells.
00:17:05.390 There are populations of cellsthat have the ability to divide.
00:17:10.040 We call this mitosis.
00:17:11.359 It’s a process by which cells can actually
00:17:13.069 divide, and take DNA with them,and then give rise to other cells.
00:17:17.430 We call those cells that divide and moveout, we call those daughter cells.
00:17:21.760 We call the cells that give rise to themprogenitor cells, but they are effectively
00:17:25.829 stem cells that give rise to thesewhat we call daughter cells.
00:17:29.550 Those daughter cells then become
00:17:31.950 the various types of cellsthat make up the hair.
00:17:35.770 When you see a hair,
00:17:37.240 you’re not seeing somethingthat grows throughout the lifespan.
00:17:40.240 You’re seeing something that’s going to be
00:17:42.270 born down there in that little cave,then is going to grow.
00:17:46.270 It’s actually going to stackup on top of itself.
00:17:48.720 That’s because hairs are madeup of a protein called keratin.
00:17:51.480 There are a bunch of different kinds
00:17:52.440 of keratin depending on whatkind of hair you’re looking at.
00:17:54.990 But these are little proteins that stackup on top of one another,
00:17:58.330 and they’re structured in a waythat makes them pretty darn durable.
00:18:01.680 I mean, it’s possible, of course,to pull a hair out.
00:18:04.280 But if you’ve ever tried to tear a hair,in particular,
00:18:06.970 thick hair like one from the face or evenone off the top of your head,
00:18:10.710 it’s actually a prettytensile strong little thing.
00:18:13.890 That’s because keratins stack up on top
00:18:16.070 of one another and bind to oneanother with a really strong bond.
00:18:20.170 What you end up with is a bunch
00:18:21.790 of proteins stacked up on top of oneanother, and that’s the actual hair.
00:18:26.000 We’ve got the hair shaft, the hair root,
00:18:27.840 and then we’ve got the stem cells downthere in that pocket that give rise
00:18:30.870 to the various cellsthat make up the actual hair.
00:18:33.880 We also have down there in that little
00:18:35.600 cave, which, by the way,is actually called the hair bulb,
00:18:38.040 if you really want to know the technicalname because it’s shaped like a bulb.
00:18:41.320 We have not just stem cells,but we have cells that give rise
00:18:45.550 to the pigment of the hairthat create what’s called melanin.
00:18:49.600 Now, some people have very blond hair,
00:18:51.510 very light hair,some people have darker hair.
00:18:54.250 But everybody, unless they have what’s
00:18:56.790 called the albino mutation,where the hairs are truly white,
00:19:00.470 they lack all melanin,and it’s a pretty rare condition,
00:19:03.410 although it does happen,most people have some degree of melanin
00:19:06.590 in their hairs because there are littlepockets of melanin-producing cells.
00:19:11.270 Melanin is just a protein that essentially
00:19:13.630 gets injected into the keratin, intothe hair, and gives it its darker color.
00:19:18.800 Now, there are a couple other components
00:19:20.360 about the hair that you need to knowabout, especially if you’re interested
00:19:23.630 in reversing hair loss orreversing graying of hair.
00:19:27.800 One of those components is a little gland.
00:19:30.560 Next to every hair rootwithin the dermal layer of the skin,
00:19:34.950 so this is below the epidermis,there is a gland called the sebaceous
00:19:39.550 gland, and the sebaceous gland makes oilystuff, and the oily stuff is called sebum.
00:19:44.120 I know the name evokes something gross,
00:19:46.480 but sebum is actually reallycool and really important.
00:19:49.030 The sebum gets injected, or seeps rather,
00:19:53.110 into the area right around the hairas the hair starts to approach the surface
00:19:58.270 where it goes from essentiallyroot to shaft.
00:20:01.890 The sebum does two things.
00:20:03.450 First of all, it forms a little bit
00:20:05.230 of a seal right at the placewhere the hair exits the skin.
00:20:08.670 And that seal is very important,actually, for waterproofing of your skin.
00:20:12.910 So we don’t often think of ourselves aswaterproof because we are so accustomed
00:20:17.190 to water just landing on ourskin and and rolling off.
00:20:20.160 But that’s because of someof the oily properties of our skin.
00:20:23.000 Now, it’s also true that our skin ispretty densely packed with cells.
00:20:26.110 But in the absence of sebum,we would not be as waterproof as we are.
00:20:31.040 Now as I mentioned, sebum hastwo important properties.
00:20:33.510 The other important property of sebum is
00:20:35.670 that it actually is a strongantibacterial and antimicrobial.
00:20:41.080 Most people don’t realize this,the oils of your skin provide a lot
00:20:44.510 of immune boundary,so that things don’t get into the hair
00:20:47.510 root or the region aroundit and infect our skin.
00:20:50.670 So sebum, while the name is sortof unattractive, to be honest,
00:20:55.070 is actually performing some essentialroles both for waterproofing and for our
00:20:59.280 immune system function, protectingus from various kinds of infection.
00:21:02.510 We’re going to return to sebum later.As it turns out,
00:21:05.710 sebum is also very important as it relatesto psoriasis and as it relates to some
00:21:10.230 of the fungal componentsthat can cause hair loss.
00:21:13.600 So I’m just going to file that away.
00:21:15.320 There’s another important component
00:21:16.870 of the region around hairs,which is the arrector pili muscle.
00:21:21.070 The arrector pili muscle is a muscle
00:21:22.990 that lies diagonally between that bulbportion of the hair or a little bit above
00:21:27.270 it, and goes up to thesurface of the skin.
00:21:29.590 The arrector pili muscle
00:21:31.530 is a muscle that contracts when weget cold or when we get scared.
00:21:37.390 So if you’ve ever had goosebumps,that’s because the arrector pili muscle
00:21:42.110 contracts pulling the skin at the surfacedown around the little hair follicles,
00:21:47.630 or at least where the hairsmeet the surface of the skin.
00:21:50.780 And so those little bumps are actuallywhere little micro hairs reside.
00:21:54.310 And the dimples between them are
00:21:56.670 the dimples that occur when thisarrector pili muscle pulls down.
00:22:00.870 Now, why would this muscle exist?
00:22:02.680 It has a couple of important functions.
00:22:04.230 One of the functions is that when it
00:22:06.150 pulls down, it causes, as the namesuggests, the hairs to stand up.
00:22:11.760 Maybe not perfectly vertical,
00:22:13.000 but when you hear, oh, I was sofrightened, my hair stood up on end.
00:22:16.310 And that’s becausethe hair has become erect.
00:22:18.750 They stand up.
00:22:20.040 Now, why would thishappen when we get cold?
00:22:22.190 It happens because when the hairs stand
00:22:24.630 up, air can be trapped between thosehairs and can actually warm our body.
00:22:29.730 This is not so much the case if youhave very light hair on your skin.
00:22:34.080 If you’re a very hairy person,
00:22:35.520 this is going to be a more robustaspect of your physiology.
00:22:38.310 And yes, this is why dogs like Huskies cango out in the snow and still remain warm.
00:22:43.470 When they get cold,
00:22:44.550 their hairs actually stand up a bit on endbecause of the contraction of these
00:22:48.960 arrector pili muscletrapping air in there.
00:22:51.000 And then their body warms the hairtrapped beneath the hair.
00:22:53.600 And it’s like they’ve got a blanket
00:22:55.070 on made by the interface between the hair,the air, and their skin.
00:23:00.390 So just to recap all the components
00:23:02.360 of hair and the different things around itthat are going to be relevant
00:23:05.550 for understanding howto replace hair that’s lost.
00:23:08.590 We have the hair itself,which has the shaft that sticks out over
00:23:14.160 the skin, goes a little bit into the skin,but basically sticks out over the skin.
00:23:17.430 We have the root portionwhich goes down into the skin.
00:23:21.360 It goes through the epidermisand into the dermis.
00:23:23.550 Then we have this bulb likeregion down at the bottom.
00:23:26.230 Down at the bottom of that bulb,we have stem cells that actually give rise
00:23:30.230 to the actual hair, and we havepigmented cells that pigment that hair.
00:23:34.530 In addition, and this is very important,there are capillaries that go
00:23:40.750 into that bulb region down at the bottomof the hair and that can serve and support
00:23:46.550 the stem cells, the melanin producingcells, which are called melanocytes.
00:23:51.120 So the melanin producing cells in the stem
00:23:52.830 cells get a lot of blood flow that allowsthem to keep providing new hair or
00:23:58.190 the proteins that make up hairand the pigment that goes into those hairs
00:24:02.590 and those little capillaries deliver notjust nutrients and things of that sort,
00:24:07.800 but they also deliver oxygen because itturns out that the whole process
00:24:11.350 of growing more hair isa very active process.
00:24:14.230 Now, as soon as you hear oxygen and you
00:24:16.310 hear that the growth is an active process,that should cue you to why so many
00:24:21.270 of the stories around how to keep yourhair and regrow hair involve statements
00:24:26.350 like don’t wear a hat,it’ll make your hair fall out.
00:24:29.040 Or if you want your hair to grow back,
00:24:30.770 don’t wear hats or massage yourscalp or increase blood flow.
00:24:34.390 Or why some people will suggest
00:24:36.510 that people take peppermint oil,for instance,
00:24:38.870 or menthol type oils of differentkinds and massage them into the scalp.
00:24:42.960 Things that make the scalp tingle.
00:24:44.550 Or there will be lighttherapies designed to what?
00:24:47.670 To increase blood flow to the scalp.
00:24:51.040 The whole rationale there is that you’re
00:24:53.070 trying to increase blood flow to the stemcell and the melanocytes populations
00:24:57.030 that support the hairsand that actually create the hairs.
00:25:00.000 Now, whether or not those are approacheswork we’ll touch on a little bit later.
00:25:03.360 I’ll just give you a little bit of a hint
00:25:04.910 right now, which is that while no singleone of those approaches that I described
00:25:10.310 is known to regrow hair in a very robustway because of the requirement for oxygen
00:25:16.870 and nutrients and because it’s suchan active process for the stem cells
00:25:20.910 and melanocytes to grow and darkenthe hairs that grow out of your skin.
00:25:25.290 It is true that manipulations ortreatments that increase blood flow
00:25:30.790 to those regions can at least slowthe loss of hair or can even extend
00:25:37.710 the duration over whichhairs continue to grow.
00:25:40.840 So if you’ve heard things like don’t weara hat, if you want to maintain your hair.
00:25:44.040 Or massage your scalp,if you want your hair to grow faster.
00:25:46.990 In some sense that’s true,but none of those manipulations on their
00:25:51.150 own is going to robustly enhancethe rate of of your hair growth.
00:25:55.880 Those things are designed to be done
00:25:57.350 in conjunction with some other treatmentsthat have been shown in many,
00:26:02.030 many clinical studies to increasethe rate and duration of hair growth.
00:26:05.560 So now you have in mind a picture
00:26:07.120 of what’s happening at the levelof individual hairs.
00:26:09.480 And if you’re anything like me,you’re probably thinking, Wow,
00:26:11.830 there’s a lot going on down therejust below the surface of the skin.
00:26:15.760 And indeed there is.
00:26:16.720 But really the things to think about arethat stem cell population that actually
00:26:19.750 give rise to the hair proteins sothat actually create the hair.
00:26:23.530 The melanocytes that darken that hair,that give it pigment.
00:26:27.050 That sebaceous gland and the oil sebumthat provides some important antimicrobial
00:26:33.050 and other propertiesto that general region.
00:26:35.590 And that arrector pili muscle,that arrector pili muscle,
00:26:38.830 as I mentioned earlier,is important for creating goosebumps
00:26:42.510 and it’s important for keepingHuskies warm in cold environments.
00:26:45.720 But it’s doing some other really important
00:26:47.470 things as well, and we’ll talk aboutthose as time goes on in this episode.
00:26:51.970 Right now, what I want to do is just talk
00:26:54.830 for a moment about how hairs actuallygrow and why they grow the way they do.
00:26:59.870 This is extremely important toward
00:27:01.950 understanding hair replacementand slowing hair loss.
00:27:07.170 There are three basicphases of growth of a hair.
00:27:11.120 The first phase is the phase
00:27:13.190 in which the stem cells down in that bulbgive rise to the cells that make up
00:27:18.590 the proteins of the hair,so the actual growth of the hair.
00:27:21.590 And keep in mind that the hair isactually growing from the bottom up.
00:27:26.560 Now, you might think, of course,it’s growing from the bottom.
00:27:28.430 Everyone knows that.
00:27:29.440 But a lot of people think that the hair
00:27:30.840 starts growing rightat the surface of the skin.
00:27:32.800 That’s not the way it works.
00:27:33.770 The hair is actually growing from deepwithin the root and stacking up and then
00:27:37.750 eventually extends outacross the top of the skin.
00:27:42.210 That growth phase iscalled the anagen phase.
00:27:46.600 A-N-A-G-E-N.
00:27:47.950 And this for some people will ring a bellbecause if you’ve ever been interested
00:27:52.990 in weightlifting or even if you’rean endurance runner,
00:27:55.910 you’ll hear about things that are anabolicthat promote growth, so Anna of Growth.
00:28:01.510 Or catabolic that promote breakdown.
00:28:04.710 So the first phase of hair growth is
00:28:07.070 called the anagen phase,and it’s a period of varying duration
00:28:11.510 depending on which hairin the body we’re talking about.
00:28:14.950 So the anagen or the growth phase
00:28:17.030 for hairs on the head, as I mentionedearlier, is anywhere from 2 to 8 years.
00:28:21.720 For most people, it’s goingto be about six years.
00:28:23.910 What this means is that if we were to justnot cut our hair, just let our hair grow
00:28:28.810 for 2 to 8 years,that hair would eventually grow
00:28:33.190 to a length that it was at itsmaximum and then would stop growing.
00:28:38.110 So we can say that the anagen phaseof hairs on the scalp is 2 to 8 years.
00:28:43.770 The the duration of the growth phase.
00:28:46.250 Contrast that, for instance,
00:28:47.990 with the duration of the anagenphase for hairs of the eyebrows.
00:28:52.750 The hairs of the eyebrows growabout 4.2mm per month.
00:28:59.080 Believe it or not, peoplehave measured this thing.
00:29:00.760 Now that’s an average.
00:29:01.790 So some people are going to have eyebrowsthat grow much longer per month.
00:29:07.360 I’m somebody who, for instance,has mostly the same length eyebrow hairs,
00:29:11.800 but every once in a while I get oneof those eyebrow hairs that really seems
00:29:14.640 to be heading off my head,like really wants out of there.
00:29:16.880 And so it’s much longer than the rest.
00:29:18.760 What does that mean?
00:29:19.790 Does it mean that it grew faster?
00:29:21.770 Maybe.
00:29:22.870 But chances are the stem cell populationin that particular eyebrow follicle
00:29:29.350 for that one eyebrow hairis longer than it is for the others.
00:29:34.960 This is really important.
00:29:35.960 I’m trying to illustrate twoprinciples at once here.
00:29:38.390 The first principle is that differenthairs on your body,
00:29:41.920 including the hairs on your scalp, havea growth phase of different duration.
00:29:45.280 This is why the hairs on your head cangrow very, very long because they have
00:29:48.190 a very long anagen or growth phase,and the hairs on your eyebrows will only
00:29:52.470 grow for a few months before theyactually fall out and then have
00:29:56.710 to undergo replication of the stem cellsto give you new eyebrow hair to then grow.
00:30:03.320 What’s important here is not justthat there are differences in the duration
00:30:06.950 of the growth phase,but rather that the rate of hair growth
00:30:11.270 is not something that tends to differwithin a given body region.
00:30:16.720 You’ll hear people say, “Oh,
00:30:18.040 my hair grows really,really fast.” Other people will say, “Oh,
00:30:20.670 my hair grows really, really slowly.’That is probably not the case.
00:30:25.120 Well, there could be slightdifferences in the rate of growth.
00:30:27.510 That is the addition of more keratin
00:30:29.750 to the actual hairs,so creation of more hair more quickly.
00:30:35.240 Almost certainly what’s happening isthat the duration of the anagen phase
00:30:38.990 in some people is just much longerthan it is in other people.
00:30:43.360 We don’t realize this,and we tend to think more in terms of how
00:30:46.510 fast hair grows,because if you were to just look
00:30:49.040 at somebody’s hair, you’d say, “Oh,they’re all more or less the same length.”
00:30:52.240 I mean, some people’s bangs are shorterthan the back because they cut them.
00:30:54.800 But if they were to just grow their hair,you’d say, “Oh, it’s all more or less
00:30:57.200 the same length.” But if we were to zoomin with a microscope,
00:30:59.870 we would see that there are a lotof hairs down there in between the other
00:31:03.590 hairs that are very,very short or even tiny, tiny, tiny.
00:31:07.050 Those are coming in as the other onesare finishing their anagen phase.
00:31:10.970 That’s the anagen or growth phase.
00:31:12.750 After the anagen phasecomes the catagen phase.
00:31:17.080 Again, this resembles the wordcatabolic or the breakdown phase.
00:31:21.150 During the catagen phase,the hair is actually receding not
00:31:26.270 from the top down to the skin surface andthen into the root, but the other way.
00:31:31.630 It’s actually receding from that bulbregion up toward the surface.
00:31:36.530 That catagen phase is going to also be
00:31:39.280 of different duration dependingon which area of the body you’re in.
00:31:42.650 It will vary a little bit depending on
00:31:44.960 who you are, meaningfrom person to person.
00:31:46.800 We’ll talk about the influences on theanagen and catagen phase in a moment.
00:31:50.310 Why is it important that it actuallyrecedes from the inside out?
00:31:53.830 Well, that’s important because as it doesthat, there’s actually a change
00:31:58.550 in that bulb region down below,because normally, there’s an interface,
00:32:02.720 there’s a conversation that’s occurringbetween the stem cell population,
00:32:06.200 the melanocytes, and the hair itself,and they support each other.
00:32:09.320 Remember, there’s blood vessels going
00:32:10.590 into that area or rather capillariesthat are feeding that area as well.
00:32:15.080 After the catagen phase comesthe telogen phase, which means rest.
00:32:19.550 The telogen phase is a period in which no
00:32:22.110 new hair proteins are beingadded by those stem cells.
00:32:25.810 During that telogen phase,
00:32:27.430 that bulb down there at the bottom,instead of being nice and oval and really
00:32:32.680 having a lot of space in it with all thesedifferent things like stem cells,
00:32:35.310 starts to pinch offfrom the little tube that comes down
00:32:40.120 from the surface of the skinthat normally would have a hair in it.
00:32:42.870 It starts to pinch off.
00:32:44.270 At some point, many hair follicles pinch
00:32:46.470 off that bulb region,and it recedes and dies.
00:32:49.890 When it recedes and dies,
00:32:51.350 the stem cell populationand the melanocytes go with it.
00:32:54.970 In other words,there is no longer a population of stem
00:32:57.990 cells to give rise to more hairafter that telogen phase.
00:33:03.120 There’s no longer melanocytes to pigmentthe hair, and in fact,
00:33:06.120 the hair isn’t there anymore,so there’s no hair even to pigment,
00:33:08.910 after that telogen phase, unlessit’s a hair of a particular type such as
00:33:15.230 the hair on your scalp,which can then reenter the cell cycle,
00:33:19.190 and get back into an anagen phaseand regrow more hair from stem cells.
00:33:24.490 There are three critical stages
00:33:26.190 of the life cycle of a hair that arerelevant to today’s conversation.
00:33:30.200 There’s the anagen phase duringwhich the hair grows,
00:33:32.790 there’s the catagen phase during which thehair actually starts to recede and die.
00:33:38.050 The protein is actuallydisappearing from the bottom up.
00:33:41.720 Then we have the telogen phase,
00:33:43.240 which is the phase in which the stem cellpopulation is what’s called a semi
00:33:46.950 quiescent, semiquiet, or completelyquiescent, where it’s not active at all.
00:33:52.770 Those three phases make up the life cycle
00:33:55.830 of a hair, keeping in mind that for somehairs, they can reenter the life cycle
00:34:01.510 and go back into the anagen phase,if there’s stem cells there,
00:34:05.390 and if there is oxygen there,and if there is sufficient blood support,
00:34:10.469 and—and this is a very important and— ifthere are the appropriate hormonal
00:34:15.830 signals to support growth,and there is a reduction or an absence
00:34:20.750 in the hormone signals that actuallytrigger that telogen phase.
00:34:25.130 I make this point now because muchof the rest of today’s discussion is
00:34:28.710 going to focus on why particular hormonessuch as dihydrotestosterone cause hair
00:34:35.389 loss and why inhibiting things likedihydrotestosterone can support
00:34:39.710 the preservation of hair that you haveand the regrowth of hair.
00:34:43.239 To make a long story very short,and then we’ll get into some additional
00:34:45.870 details that are relevant,and that I hope you’ll stick around
00:34:48.949 to listen to, dihydrotestosterone,which is a derivative of testosterone,
00:34:54.409 causes changes in that bulb regionwhere the stem cells reside.
00:34:59.310 It shortens or halt the anagen phase
00:35:02.710 of hair growth, and it extends andpromotes the catagen and telogen phase.
00:35:09.200 When we hear that, “Ohdihydrotestosterone makes your hair fall
00:35:12.670 out, or estrogen makes your hair grow,”there are real chemical people,
00:35:16.650 or we should say biochemicallegitimate reasons as to why that is.
00:35:20.190 But it all comes back to this three
00:35:22.350 phases of hair growth: the anagen growthphase, the catagen,
00:35:25.930 catabolic or hair loss phase,and the telogen phase,
00:35:29.430 which is a rest period in which the hairscan either come back,
00:35:33.070 if it reenters the anagen phaseor maybe it’s over for good.
00:35:36.310 Hormones are the accelerator and thebrake on each one of those phases.
00:35:40.970 I’d like to take a quick break
00:35:42.510 and acknowledge one of oursponsors, Athletic Greens.
00:35:45.430 Athletic Greens, now called AG1,is a vitamin mineral probiotic drink
00:35:50.310 that covers all of yourfoundational nutritional needs.
00:35:53.080 I’ve been taking Athletic Greens since
00:35:54.790 2012, so I’m delighted that they’responsoring the podcast.
00:35:58.160 The reason I started taking
00:35:59.120 Athletic Greens and the reason I stilltake Athletic Greens once or usually
00:36:02.750 twice a day is that it gets me theprobiotics that I need for gut health.
00:36:07.320 Our gut is very important.
00:36:08.550 It’s populated by gut microbiotathat communicate with the brain,
00:36:12.160 the immune system,and basically all the biological systems
00:36:14.790 of our body to strongly impact ourimmediate and long-term health.
00:36:19.160 Those probiotics and Athletic Greens areoptimal and vital for macrobiotic health.
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00:36:26.120 a number of adaptogens, vitamins,and minerals that make sure that all
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00:36:37.360 huberman, and they’ll give you five freetravel packs that make it really easy
00:36:41.040 to mix up Athletic Greens while you’reon the road in the car, on the plane,
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00:36:56.050 Now you have in mind the anatomy
00:36:58.070 of the hair and the area from which itgrows, and the stem cells, et cetera.
00:37:02.040 The fact that there’s capillaryinnervation delivering oxygen and blood
00:37:05.430 flow to the stem cells that give riseto the hair, and that there are these
00:37:09.830 three critical phases of hair growth:anagen, catagen, and telogen.
00:37:14.610 Now, let’s talk about the accelerators
00:37:17.070 on hair growth and thebrakes on hair growth.
00:37:20.280 There are many accelerators on hair
00:37:21.990 growth, but the first one that I reallywant to underscore is blood flow itself,
00:37:27.910 which equates to the deliveryof nutrients and oxygen.
00:37:31.650 This is very important,
00:37:33.390 and it explains a lot of the treatmentsfor halting and reversing hair loss.
00:37:38.040 For instance, one of the longest standing
00:37:40.110 treatments for halting and reversinghair loss is so-called minoxidil.
00:37:44.790 Minoxidil, sometimes also referredto by the brand name ROGAINE,
00:37:49.330 was actually a drug that wasdeveloped to treat hypertension.
00:37:53.200 This is a cardiac drug that lowers blood
00:37:56.030 pressure, and it doesthat by causing vasodilation.
00:37:59.230 It allows more blood flow,
00:38:00.990 not just to the hairs on your scalp,but to hairs everywhere on your body.
00:38:05.240 Indeed, most people don’t realize this,
00:38:07.070 but minoxidil won’t just slow the lossof hair from your scalp,
00:38:11.670 it is also effective at slowingthe loss of hair elsewhere in your body.
00:38:15.510 How does it do that?
00:38:17.050 Well, you now know oneof the major ways it does that.
00:38:20.110 It does that by extending the anagenphase, so it basically makes that phase
00:38:25.950 a bit longer, and does it make itmuch longer, which is why for most people
00:38:30.630 who are losing their hair quicklyor who have already lost their hair,
00:38:34.190 minoxidil alone is not goingto be a sufficient treatment.
00:38:37.240 However, minoxidil has been shown to beeffective at slowing rates of hair loss
00:38:41.880 in people that are startingto experience some hair loss.
00:38:44.080 I’ll get into dosages and things
00:38:45.400 of that sort a little bit later,but right now I just want to really focus
00:38:48.350 on the logic of why people would takethis drug,
00:38:51.150 which is lowering hypertensionat all as it relates to hair loss.
00:38:56.050 That might seem like crazy until you
00:38:57.990 understand the anatomy and the growthof hairs, which you now do.
00:39:01.440 That’s what minoxidil is doing.
00:39:02.790 It’s creating more blood flowto the hairs, which because minoxidil
00:39:07.720 does have this positive effect,at least most people would like to slow
00:39:11.070 their rates of hair loss on their scalpanyway, it tells you that blood flow
00:39:15.910 and delivery of oxygen and othernutrients from the blood is pretty
00:39:19.830 critical, if not very critical, for thesupport of the hair growth cycle itself.
00:39:25.890 Now, again, we haven’t talked at all aboutthe sorts of chemicals or the signals
00:39:30.240 within the body, such as hormonesthat actually direct the growth of hairs.
00:39:33.920 Here, we’re just talking about
00:39:34.950 a mechanical change,allow more blood flow to the region,
00:39:38.070 and thereby extend the anagen phase, whichis exactly what happens with minoxidil.
00:39:42.370 Now, minoxidil does have other effects,and this is why dosing of minoxidil
00:39:46.670 becomes a little bit complicated and canbe a little bit tricky to troubleshoot.
00:39:51.130 It can greatly lower blood pressureor lower blood pressure just a little bit,
00:39:55.350 depending on how sensitive somebodyis to that particular drug.
00:39:58.930 Oftentimes physicians will start peopleon Minoxidil dosages that are very low.
00:40:03.030 Ideally, that would be the case and thenratchet it up in order to figure out
00:40:07.160 where the minimal effective dose or thecritical threshold is beyond which they
00:40:11.150 start experiencing some prettyuncomfortable side effects,
00:40:14.430 such as swelling of the anklesor headaches or dizziness.
00:40:18.470 These things can happen with the useof Rogaine, aka Minoxidil.
00:40:22.490 Now, Minoxidil has also been associatedwith increases in the hormone prolactin.
00:40:27.810 Prolactin is a hormone that’sreleased from the pituitary.
00:40:31.390 It is a hormone that acts also as a bitof a neurotransmitter, like many hormones,
00:40:36.830 and it tends to be antagonisticor an opposite to dopamine.
00:40:41.410 Dopamine is a neurochemical.
00:40:43.560 It’s actually a neuromodulator,
00:40:45.000 meaning it modulates the activity of abunch of neural circuits in the brain.
00:40:48.030 It also controls the releaseof various hormones in the body.
00:40:51.510 Dopamine is almost always associated withstates of motivation, pursuit, and drive.
00:40:57.030 It has a little bit of a feel- good
00:40:59.240 element to it,which is why a lot of people think
00:41:01.080 dopamine is associatedwith reward and pleasure.
00:41:03.390 But it’s really about energy,motivation, and drive.
00:41:06.990 Dopamine and prolactin are,
00:41:08.800 as I mentioned before,antagonistic to one another.
00:41:10.990 They’re in sort of a push-pull.
00:41:13.080 People who take Minoxidil,especially if they’re very sensitive to it
00:41:16.150 or they take dosages that are too high,will experience increases in prolactin
00:41:20.750 that in turn can cause things likereductions in libido,
00:41:25.630 reductions in overall feelingsof well-being, apathy,
00:41:29.310 and in some cases where the elevationsin prolactin are more extreme,
00:41:33.630 they can experience, for instance,increase in male breast tissue
00:41:37.430 gynecomastia or even small bitsof milk letdown, things of that sort.
00:41:42.350 In women who take Minoxidil,
00:41:44.350 the side effects are much likethe ones in experienced in men.
00:41:48.200 So there can be swelling,
00:41:49.190 edema of the tissuesbecause if you get too much vasodilation
00:41:52.990 and too, too much lowering of bloodpressure, that’s not good.
00:41:56.230 Headaches, dizziness and so on.
00:41:58.090 Dosing of Minoxidil is really important.
00:42:00.330 If somebody is going to use Minoxidil
00:42:03.030 in order to try and slow or reverse hairloss, again, it mainly is going to be used
00:42:07.850 to slow rates of hair loss,not to actually reverse hair loss.
00:42:10.920 The really key thing isto get that dosage right.
00:42:13.360 The ranges of Minoxidil that you’ll see
00:42:15.030 suggested and that peopleuse out there are vast.
00:42:18.600 I should also mention that there are two
00:42:20.510 major routes by which people getMinoxidil to the hair follicle.
00:42:23.710 One is to take it systemically as a pill
00:42:25.800 where it goes into thegeneral circulation.
00:42:27.810 The other is to take ittopically as a cream.
00:42:30.810 There are prescription and non-
00:42:33.240 prescription forms of Minoxidiljust to further complicate things.
00:42:36.310 But the ranges of oral Minoxidilthat you’ll see out there and that people
00:42:40.550 take range anywhere from 0.25 milligramsall the way up to five milligrams per day.
00:42:47.920 That’s an enormous range.
00:42:48.950 It’s like a 20-fold range.
00:42:51.530 The topical Minoxidil is alsofound in various concentrations.
00:42:56.180 The typical concentration is going to be
00:42:58.310 a 5% concentration that peoplewill use once per day.
00:43:01.630 Topical treatment with Minoxidil at 5%
00:43:04.710 concentration is thought to just stayat the scalp, but we now know that it
00:43:10.120 can go systemically, it can getinto the general bloodstream.
00:43:13.040 Why that is should make complete sense
00:43:14.520 to you because when you put somethingon your scalp, I’ve already told you
00:43:17.190 that these little pits,these little tubes that go down to those
00:43:20.710 bulb regions below the skin that havedirect access to the blood supply.
00:43:26.600 When you massage something into your
00:43:27.920 scalp, it not only has the opportunityto get into your general circulation,
00:43:31.630 it often does,especially if it’s something that’s very
00:43:35.630 water-soluble and that way can getinto the capillaries and into the general
00:43:39.870 bloodstream, although topical treatmentsof which we’re going to discuss,
00:43:44.030 a number of them today don’t tend to getinto the general circulation as robustly
00:43:48.870 as taking somethingby way of pill or capsule.
00:43:52.730 Minoxidil works by way of increasing blood
00:43:55.310 flow to the stem cellniche below the hair.
00:43:58.410 The dosage ranges of the oral Minoxidil
00:44:01.510 are tremendous, 0.25 milligrams, all theway up to five milligrams once per day.
00:44:06.330 The dosage range of the topical solutionstends to be a little bit more confined.
00:44:10.990 Typically, it’s a 5% solution and it’s
00:44:13.190 recommended that peopleuse it one time daily, maybe twice daily.
00:44:17.430 It’s also important, by the way,if you’re going to take this route,
00:44:20.830 that you actually leave that solutionon the scalp for 3-5 minutes.
00:44:24.320 This is important and should makecomplete sense as to why it’s important.
00:44:27.440 You can’t just rub the stuff into your
00:44:28.880 head and then rinse it offand expect it to be absorbed.
00:44:31.190 It actually needs to seep down into thosehair follicles and access the niche.
00:44:36.230 How do people arrive at thecorrect dosage for Minoxidil?
00:44:40.870 Well, for better or for worse, really,in some cases,
00:44:44.710 it’s accomplished by finding out that youhave an unwanted side effect, like
00:44:50.530 dizziness or swelling of your ankles oredema or I would hope this wouldn’t be
00:44:55.310 the case, but something that suggeststhere’s hyperprolactinemia.
00:44:59.480 You could get a blood test to measure
00:45:01.070 your prolactin or you perhaps noticea drop in libido or some lethargy.
00:45:05.930 These sorts of things that are common
00:45:07.830 to reduce levels of dopamine,increased levels of prolactin.
00:45:11.000 I would hope that if people are workingwith a physician or if they’re not
00:45:14.030 in taking Minoxidil, that they wouldstart with the lowest possible dose.
00:45:19.770 For oral Minoxidil,that would be 0.25 milligrams and then
00:45:23.290 increase it as needed rather than jumpingin right at five milligrams because some
00:45:27.440 of those side effects,in particular the fluid retention
00:45:30.120 and the hyper prolactinemiacan be pretty uncomfortable and can
00:45:33.270 disrupt a lot of aspects of lifethat most all of us consider desirable.
00:45:37.770 We’re really focusing right nowon treatments that relate
00:45:40.750 to the critical requirement for hair stemcells to receive blood flow in order
00:45:46.310 to receive oxygen and nutrients,to get the hair to grow.
00:45:50.130 That’s really what Minoxidil is about.
00:45:52.430 It’s also what all of those anecdotesyou hear are all about, like
00:45:57.770 massaging the scalp or puttingred light on the scalp.
00:46:01.480 Although red light might do some other
00:46:02.710 things, in general,heating or lighting of the scalp or
00:46:05.910 massaging of the scalp is really designedto increase blood flow to the scalp.
00:46:10.430 Now, the reason Minoxidil works at all isbecause it is going to increase blood
00:46:15.560 flow around the clock,and that’s because people are taking it
00:46:18.150 topically and it’s seepinginto the general circulation,
00:46:21.110 or at least it stings somewhatrestricted to the hair cell niche.
00:46:25.120 Or they’re taking it orally and it makes
00:46:26.630 it to that hair cell nichebelow the follicle.
00:46:31.240 When we massage our scalp, however,
00:46:33.630 that’s a transient thing,like I massage my scalp right now,
00:46:36.630 I’m no doubtincreasing blood flow to certain areas
00:46:40.040 and probably decreasing blood flowto the areas I’m pushing down on.
00:46:42.470 But it’s all temporary.
00:46:43.710 I don’t know many people that can massagetheir scalp enough during the day or long
00:46:48.310 enough during the day rather that itwould sufficiently increase blood flow.
00:46:52.440 With that said,
00:46:53.150 it is clear that increasing blood flowto the scalp by way of reducing
00:46:57.230 hypertension,which is effectively accomplished
00:47:00.110 by broadening by expanding the bloodvessels and capillaries,
00:47:05.070 is an effective way to at leasthold on to the hair that you have.
00:47:09.830 Is it going to completely halt hair loss
00:47:12.120 if you have a strong geneticbias towards hair loss?
00:47:14.230 No.Is it going to reverse hair loss?
00:47:16.750 Very unlikely that it will.
00:47:18.270 But it can slow hair loss or evenmaintain the hair that you have.
00:47:22.530 If we were to take a step back and askourselves what other sorts of drug
00:47:26.790 treatments are out there besidesMinoxidil, that increase blood flow
00:47:30.870 and that might increase the rates of hairgrowth or more likely increase
00:47:35.750 maintenance of hair that one already hasby increasing blood flow to the niche.
00:47:39.970 Nowadays, there are more and more doctors
00:47:42.110 who are familiar with thisrequirement for blood flow.
00:47:45.170 Understand the mechanismsby which Minoxidil works and understand
00:47:48.400 the vast desire out there for peopleto hold on to the hair they have
00:47:51.190 and regrow hair and they are prescribingthings like low-dose tadalafil,
00:47:56.110 so 2.5 milligram to fivemilligram tadalafil.
00:48:00.690 Tadalafil was initially discoveredas a drug to treat prostate health.
00:48:05.110 It was a drug that we now know canincrease blood flow to the prostate
00:48:08.990 and thereby offset some of the issuesassociated with an aging prostate.
00:48:13.970 Higher doses of tadalafil
00:48:16.450 sometimes also referred to by its brandname, which is Cialis,
00:48:20.230 are used to treat erectile dysfunction,but at the dosages that are used
00:48:23.830 to increase blood flow to the prostateand that now a number of doctors are using
00:48:28.270 to increase blood flow not justto the prostate but to all regions
00:48:31.550 of the body, including the scalp,such as 2.5-5 milligram tadalafil.
00:48:37.960 This is something that I think deserves
00:48:40.030 attention because it falls underthe umbrella of increasing blood flow
00:48:43.670 to the hair stem cell nichein order to maintain hair.
00:48:47.690 It is not something that most doctorsare going to be familiar with as the way
00:48:52.390 to reverse hair lossbecause it won’t do that.
00:48:55.390 But the use of low-dose tadalafil
00:48:57.270 to slow rates of hair loss is very muchin a logical mechanistic sense,
00:49:03.170 exactly the same as the logic of usingMinoxidil to slow rates of hair loss.
00:49:07.390 It’s all about increasing blood flow
00:49:09.400 to support the stem cell nichebelow the hair follicle.
00:49:12.110 The critical requirement for blood flow,oxygen and nutrients to the stem cell
00:49:16.790 niche is also why you hear a lot nowadaysabout the use of PRP,
00:49:21.430 platelet-rich plasma for trying to offsethair loss or even reverse hair loss.
00:49:27.370 We’re going to do an entireepisode about PRP.
00:49:30.050 It is pretty controversial in certain
00:49:32.230 circles and well- acceptedin other circles.
00:49:34.800 A couple of key thingsto understand about PRP.
00:49:37.010 First of all,
00:49:37.870 it is being used in multiple tissues fordifferent purposes in different clinics.
00:49:42.890 For instance,
00:49:44.240 board-certified physiciansin the United States, Canada,
00:49:46.950 and Europe are doing PRP injectionsinto ovaries to try and expand the number
00:49:53.830 of healthy follicles and eggs sothat people can conceive later in life or
00:49:58.320 even earlier in life if theydon’t have many follicles.
00:50:00.360 People are getting PRP injections
00:50:01.910 into their joints in orderto try and support joint health.
00:50:05.750 People are getting PRP injections intojust about every tissue you can think of.
00:50:10.010 However, PRP, despite what you mayhave heard, is not stem cells.
00:50:15.400 Somebody tells you they’re injecting stemcells, they’re either outside the US,
00:50:18.570 Canada, or Northern Europe,or they’re injecting something else.
00:50:21.750 So you want to really look into that.
00:50:24.070 The safety issues there are subjecttotally deserving of an entire episode.
00:50:29.990 I’m not necessarily opposed to the futureof stem cells as a treatment,
00:50:34.320 but keep in mind that stem cells arecells that can give rise to lots of other
00:50:37.230 cell types, and they are cellsthat divide and replicate.
00:50:40.920 There’s a name for that when it happens
00:50:42.520 in the adult body whenyou don’t want that.
00:50:44.490 That’s called cancer.
00:50:45.790 Tumors are over-production of cells
00:50:48.510 from stem cells when those stem cellsordinarily should be quiescent.
00:50:52.840 Keep in mind the differencebetween stem cells and PRP.
00:50:55.110 PRP, platelet-rich plasma,
00:50:57.690 again, is legal in the US and many otherplaces because it involves drawing
00:51:02.270 somebody’s blood,spinning it down at a particular speed,
00:51:05.680 which separates out differentcomponents within the blood.
00:51:08.590 Then taking the platelets and re-
00:51:10.790 injecting those in a solutionback into the person’s body.
00:51:16.090 Platelet-rich plasma or PRP is plateletenriched plasma from that person.
00:51:21.990 But the basis of PRP is reallyto encourage nutrient delivery
00:51:26.230 to a particular region in the body usingsomebody’s own platelets,
00:51:29.840 because those platelets areenriched for various nutrients.
00:51:32.810 People are getting PRPinjections into their scalp.
00:51:36.560 Those are not stem cell injections.
00:51:38.070 Those are PRP injections into the scalpwith some moderate success.
00:51:42.760 These are very expensive treatments.
00:51:44.470 They tend to be transiently successful.
00:51:47.080 I’m sure there are people out therewho are going to say,
00:51:49.030 “PRP worked fabulously wellfor me.” That might be the case.
00:51:52.280 I’m not going to dispute that.
00:51:53.510 And I’m happy for you.
00:51:54.670 Although there are not sufficient
00:51:56.920 clinical data to suggest PRP asa treatment right now,
00:51:59.440 especially given the cost, many thousandsof dollars, many, many treatments.
00:52:02.990 It’s also the case that the PRP
00:52:06.110 injections, when they work, might workfor reasons independent of the platelets.
00:52:12.120 What do I mean by that?
00:52:12.960 Well, soon, we’re going to talk abouta different type of treatment,
00:52:15.790 which is a mechanical manipulationof the hair follicle, typically,
00:52:19.840 on the scalp, because that’s typicallywhere people want to regrow hair.
00:52:22.080 I don’t know many people who are trying
00:52:23.310 to maintain or accelerate or regrowtheir back hair, for instance.
00:52:28.040 They might be out there,
00:52:28.950 but I don’t think there are a lot of themor their leg hair, for that matter.
00:52:33.320 Almost always,it’s going to be scalp hair.
00:52:35.070 And one way that people are doingthat is through mechanical stimulation
00:52:39.210 of the hair follicle and the stem cellniche using what’s called micro-needling.
00:52:43.190 Micro-needling, as the name suggests,
00:52:45.110 is taking a bunch of littleneedles either in a little stamp.
00:52:48.890 A little square or nowadays,typically, it’s a roller.
00:52:52.280 It looks like a paint roller,
00:52:53.750 except it’s got tons of littleneedles in rows all over that roller.
00:52:58.470 Those needles range in length from halfa millimeter to 2.5 millimeters.
00:53:04.850 Millimeters and one rollsthat over the scalp.
00:53:08.400 If you’re thinking, ouch,that probably hurts.
00:53:10.390 Indeed, it can hurt a little bit or a lot,
00:53:12.550 depending on the thicknessand the length of those needles.
00:53:17.010 Micro-needling has beenshown to do two things.
00:53:20.030 It has been shown to reactivate semi-
00:53:23.440 quiescent populations of stem cellsthat are in that telogen phase,
00:53:26.750 putting them back in antigen phaseand thereby stimulate more hair growth.
00:53:30.510 It has also, and this is I think,the best use of micro-needling.
00:53:33.910 It has also been shown to be a very
00:53:36.070 effective augment for some of the hormone-based hair regrowth tools
00:53:41.800 and pharmacology that we’re goingto talk about in a few minutes.
00:53:44.960 Micro-needling and PRP have somethingvery critical in common,
00:53:48.070 which is the needle,the actual injection into the skin.
00:53:51.920 For those of you that are hearing this
00:53:53.110 and thinking,why would disrupting the skin with needles
00:53:56.630 actually, support hair growth or regrowth,wouldn’t that just damage the follicle?
00:54:02.090 Well, this gets into some of the, I think,interesting, if not fascinating aspects
00:54:07.190 of our biology,which is that all of the cells in our body
00:54:10.470 really can respond to bothchemical and mechanical cues.
00:54:14.810 When we hear needle injected into skin,we think, oh, that must just be damaging
00:54:19.150 everything, causing allsorts of inflammation.
00:54:21.550 But it turns out that low levelsof inflammation caused by things like
00:54:25.550 micro-needling or PRP injections or eventhe introduction of any kind of fluid.
00:54:31.240 For instance, saline fluid injected
00:54:33.110 into a region can cause changesin the cells in that region, causing,
00:54:37.990 for instance, stem cell populationsthat were waning to reactivate again,
00:54:42.790 causing telogen phase follicles that havemelanocytes and stem cells that are dying
00:54:48.790 off but not completely goneto reenter the cell cycle.
00:54:53.410 Micro-needling procedures, PRP injections,things like Minoxidil,
00:54:58.070 they all kind of center around this samegeneral theme of increasing blood flow,
00:55:03.030 increasing oxygen, delivery of nutrients,or in the case of micro-needling,
00:55:07.710 increasing inflammation just enoughat that local site that certain cascades
00:55:13.590 of biological function that relateto proliferation of stem cells or
00:55:18.430 maintenance of stem cellpopulations are kicked off.
00:55:21.160 It’s sort of like reminding the cells
00:55:22.630 in that area that they need to stay alivein order to replenish whatever is lost.
00:55:27.070 Sometimes a wound canactually induce some healing.
00:55:30.390 Although I do want to point out
00:55:32.510 that the micro part of micro-needling isabsolutely key and this should be
00:55:36.870 obvious to you whenyou think about scars.
00:55:39.790 I don’t know about you,but I’ve never seen a scar with hair
00:55:42.800 growing out of it, or if there was,it was probably like one hair.
00:55:45.950 But if you’ve ever seen a scar,
00:55:48.000 someone had their appendix out or ifsomeone had a brain surgery,
00:55:50.910 you see that scar because there isno hair growing out of it.
00:55:54.350 So the micro portion of micro-needlingis extremely important.
00:55:58.710 We are not talking about causing
00:56:00.990 significant damage to a tissue in orderto activate that stem cell population.
00:56:05.150 We’re talking about causing microdamage
00:56:07.230 and micro levels of inflammationto stimulate growth.
00:56:10.630 For those of you that are interestedin using micro-needling or micro-needling
00:56:15.040 in combination with chemical treatmentslike Minoxidil or some of the other
00:56:18.040 treatments we’ll talkabout in a little bit.
00:56:19.390 Like finasteride and caffeine.
00:56:21.640 Yes, believe it or not,caffeine is being used to regrow hair.
00:56:24.550 Very interesting.
00:56:25.680 Get into that in a moment.
00:56:26.800 But if you’re interested in using m
00:56:28.120 icro-needling alone or in combinationwith some of these other treatments,
00:56:31.600 there’s a wonderful review that wasjust published this last year.
00:56:34.510 Wonderful, because it’svery comprehensive.
00:56:36.930 Not so wonderful.
00:56:38.430 Not to the fault of the authors because
00:56:40.970 most of the studies out thereon micro-needling are not superb.
00:56:44.830 There are ways of gauging the strengthof a study mainly relate to their
00:56:48.800 duration, whether or not theywere control groups et cetera.
00:56:51.520 But the review itself is excellentand the title of the review is M
00:56:54.670 icro-needling and its Use inHair Loss Disorders: A Systematic Review.
00:56:58.640 We will provide a link to this
00:56:59.830 in the show note captions and this reviewdid a very good job of highlighting both
00:57:04.320 the strengths and drawbacks of the variousstudies looking at micro-needling.
00:57:07.910 It also explored the use of micro-needling
00:57:10.310 in both men and women and of variousages, and it does appear to be the case
00:57:15.670 that micro-needling shows some positivebenefit in both men and women,
00:57:19.270 regardless of age,especially when used in combination
00:57:22.840 with the various other treatmentsthat we’re talking about.
00:57:25.080 I was also able to glean from this reviewand some of the papers described within it
00:57:29.230 that needle lengths of about onemillimeter to 2.5 millimeters seem to be
00:57:34.070 more effective thanshorter needle lengths.
00:57:37.390 So if you’re scared of the needlesand the needle lengths,
00:57:40.510 keep in mind that done properly,micro-needling shouldn’t be too painful.
00:57:44.480 Some people experience a little bit more
00:57:46.040 pain than others, but it’s notconsidered a very painful procedure.
00:57:49.150 It is, however, a procedure that can cause
00:57:51.920 some bleeding of the scalp,and that bleeding of the scalp can be
00:57:54.880 very apparent,especially if it’s in the front
00:57:57.000 of the head as opposed to in the topof the head and hidden by some hair or if
00:58:00.550 you’re alreadyquite bald in a given region.
00:58:04.730 Keep that in mind.
00:58:05.840 I suppose one could wear a hat or a wig
00:58:07.480 or something of that sort if theywere really self-conscious about it.
00:58:09.830 But the micro-needling itself is causing
00:58:13.110 a physical disruption to the scalp,some degree of bleeding, inflammation.
00:58:17.230 And again, all of that is part
00:58:19.110 of the process by which micro-needlingcan actually improve hair growth.
00:58:23.040 Of course, there’s healing that occurs
00:58:24.760 of the bleeding and thedamage to the follicle.
00:58:26.830 This is a transient thing,
00:58:28.260 but understanding the cosmeticimplications in the short term as well as
00:58:31.960 in the long-term iscertainly worth knowing.
00:58:34.200 One thing that’s very clear is
00:58:35.470 that the combination of micro-needlingand Minoxidil treatment together is far
00:58:39.750 more effective than eitherof those treatments alone.
00:58:42.390 In addition,
00:58:43.510 the combination of micro-needlingand Minoxidil has been shown to be
00:58:47.320 effective in recoveringwhat are called dead zones.
00:58:49.850 These are regions of the scalp that areeither completely bald or mostly bald,
00:58:53.910 for which there is essentiallyno stem cell population there.
00:58:59.210 The combination of Minoxidil plus
00:59:01.480 micro-needling is somehow able to recoverthose stem cell populations and allow
00:59:05.350 new hair to grow,although the growth of that hair
00:59:08.070 in those dead zone regions can takea very long time, 30 to even 50 weeks.
00:59:13.070 Neither Minoxidil treatment alone nor
00:59:15.240 micro-needling alone has been shown to beeffective in recovering these so-called
00:59:19.310 dead zones when thosetreatments are done separately.
00:59:22.680 This, I would say,
00:59:23.430 is a strong reason to consider combiningmicro-needling and Minoxidil as opposed
00:59:28.270 to just doing Minoxidilor just micro-needling.
00:59:31.010 I should also mention that Minoxidiltreatment, if you pursue it,
00:59:35.160 is likely something that you are goingto have to do for the rest of your life.
00:59:38.950 If you want to hold on to the hair growththat you obtain with Minoxidil or if you
00:59:43.910 want to maintain the hair that you arealready maintaining with Minoxidil.
00:59:48.270 Some people have been successfulin taking Minoxidil, maintaining some hair
00:59:52.600 growth or even stimulating some hairgrowth and then coming off Minoxidil.
00:59:55.790 But most everyone who goes on Minoxidil
00:59:57.990 has to stay on Minoxidil because whenthey cease taking Minoxidil,
01:00:01.590 even if they’re doing other treatments,they lose the hair that they gained
01:00:05.790 with Minoxidil, so that isan important consideration.
01:00:08.600 The decision to go on Minoxidil is likely
01:00:10.630 a decision to be on Minoxidilfor the rest of your life.
01:00:13.480 I’d like to just take a brief break
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01:01:26.000 So, as you’re probably startingto realize, there’s a relationship between
01:01:28.870 mechanical stimulation of the follicleand blood flow, both of which turn out
01:01:33.150 to be critical for maintaining hairand for stimulating hair growth.
01:01:37.490 Not surprisingly then, an increasingly common treatment for hair loss is Botox.
01:01:42.950 Botox is the brand name for what isotherwise known as botulinum neurotoxin.
01:01:48.550 What is botulinum neurotoxin?
01:01:50.770 Botulinum neurotoxin,
01:01:52.070 sometimes just called botulinumfor short, is a toxin that’s a bacterial
01:01:56.310 toxin that serves to cut the proteinthat leads to synaptic vesicle release.
01:02:02.630 What in the world did I just say?
01:02:04.320 Well, when your nerve cells communicatewith one another,
01:02:07.150 they do that by way of electricity,but the electricity within those nerve
01:02:11.390 cells, those neurons,triggers the release of chemicals
01:02:14.350 from neurons into the synapse,the little gap between neurons.
01:02:18.090 The release of those chemicals allowsthe next neuron to be chemically active,
01:02:22.070 or in some cases, it will suppress theelectrical activity of that next neuron.
01:02:26.730 Botulinum neurotoxin serves to cuta protein present in neurons so
01:02:32.910 that neurons cannot release the chemicalsthat cause other neurons to be active.
01:02:37.930 This actually is pretty serious.
01:02:39.600 If you were to get botulinum neurotoxin
01:02:41.550 injected into your muscle you would beparalyzed because the nerves that control
01:02:46.030 contraction of the muscles would not beable to control the release
01:02:49.510 of that chemical onto the muscle,which makes it contract.
01:02:53.450 Botulinum neurotoxin is commonlyused in what’s called Botox.
01:02:57.720 Botox is something most people are
01:02:59.390 familiar with because people get itinjected in and around their wrinkles
01:03:04.310 because many wrinkles are triggeredby not just loss of tensile strength
01:03:10.070 in the skin, but rather,the nerves around the skin
01:03:14.390 and in the skin are hyper contracted,which causes wrinkles.
01:03:18.480 For instance, I have crow’s feet.
01:03:19.840 I like to think that’s because I’velaughed a lot and smiled a lot,
01:03:22.640 and it’s probably also becauseI’ve squinted a lot in my lifetime.
01:03:25.730 I have crow’s feet because the nerves
01:03:27.830 there have pinched the skin on eitherside of my eyes and that’s given me
01:03:33.160 little creases there that aresometimes referred to as crow’s feet.
01:03:36.230 Botox injections can be applied
01:03:37.950 to the scalp in orderto relieve tension of the scalp.
01:03:42.920 In hearing that, it should be obvious why
01:03:44.590 Botox is being used to tryand offset hair loss.
01:03:47.750 It’s decreasing the squinting,
01:03:50.630 if you will, or the tensile natureof the scalp skin so that more blood flow
01:03:57.190 can arrive at that stemcell follicle area.
01:04:00.410 Botox treatment to the scalp isactually becoming pretty common.
01:04:03.840 There are a couple requirementswith this Botox treatment.
01:04:06.280 First of all, it has to be doneby somebody who’s really skilled.
01:04:08.950 There are numerous images online
01:04:11.870 and websites online of so-called Botoxfails, where people have gotten too much
01:04:16.430 Botox or the injections have been donetoo deep or not at the correct locations
01:04:20.800 on people’s face or scalp, and it cangive them droopy scalp or droopy eyes.
01:04:24.350 All sorts of cosmetic nightmarescan occur with Botox.
01:04:27.940 The second thing to understand isthat Botox does eventually wear off.
01:04:31.470 That botulinum neurotoxindoesn’t stick around forever.
01:04:34.880 Provided it’s done correctlyat the correct dosages,
01:04:37.030 it doesn’t actually kill the neuronsthat cause that tension of the skin,
01:04:40.730 so Botox injections haveto be done repeatedly.
01:04:43.850 The efficacy of Botox for offsettinghair loss is not clear.
01:04:48.040 There aren’t a lot of large- scaleclinical studies on this just yet,
01:04:51.110 but it does seem to be at least onereasonably safe alternative to things
01:04:54.790 like Minoxidil, although I think if onewere to just want to increase blood flow
01:04:59.070 to the scalp, things like low- doseTadalafil, which doesn’t seem to carry any
01:05:03.080 of the side effects that Minoxidil cancarry, we talked about those side effects
01:05:06.950 earlier, that would probablybe the better alternative.
01:05:09.710 Botox is a fairly invasive procedure,but some people opt for Botox treatment.
01:05:14.030 In fact, there is a syndrome calledcutis verticis gyrata.
01:05:19.400 Some of you have probably seen this.
01:05:20.760 It’s more typical in men,although it does occur in women.
01:05:23.510 It literally means a lumping of the skinon the scalp, or gyri of the scalp.
01:05:29.730 Gyri or gyrus pertains to the Latinword knee, so it means bump or knee.
01:05:36.330 Any time you hear the word gyrus
01:05:38.170 in neuroscience or in biology,you’re talking about a bump.
01:05:41.360 You’ll sometimes see people will haveridges in the back where it looks as if
01:05:44.030 the skin was pushed together, kindof like a Shar-Pei dog, but on the scalp.
01:05:48.870 People with cutis verticis gyrata almostalways experience pattern hair loss.
01:05:54.920 Now, part of the reason for that is
01:05:56.510 cutis verticis gyratais also associated with some androgen or
01:06:01.400 testosterone- related hormone issuesthat we’ll talk about in a little bit.
01:06:04.910 But in addition to that,
01:06:06.790 it has been shown that relieving someof those gyrata by injections of Botox
01:06:10.950 to allow those folds to sit flatter,A, is effective.
01:06:14.750 It can lead to less of those gyri,those bumps, and can improve hair growth
01:06:20.350 in those regions,even if those people don’t take on any
01:06:24.070 additional treatmentsto address the hormone issues.
01:06:26.960 That’s really how people arrived at thisunderstanding that Botox might be a good
01:06:30.230 treatment in general for reducing thesquinting of the scalp that can occur
01:06:35.750 and the resulting hairloss in those regions.
01:06:38.070 I’d now like to turn our attentionto the chemical variables that control
01:06:42.190 the duration of the growth phase of hair,the duration of that catagen phase,
01:06:46.630 which is when that hair essentiallyrecedes from the inside out,
01:06:50.710 and the quiescent or semi-quiescent telogen phase.
01:06:55.850 There are a couple of key chemical playershere that we should all be aware of.
01:07:00.370 First of all, the growth factor IGF-1,
01:07:04.490 insulin growth factor 1,which is produced by the liver,
01:07:07.550 but that receives stimulationfrom the brain and pituitary to be
01:07:11.790 released, is a strongregulator of hair growth.
01:07:15.570 We can think of it asthe accelerator on hair growth.
01:07:19.490 It does that by extending that anagen,or growth phase, for longer.
01:07:24.990 It doesn’t necessarily speed up growth,
01:07:27.150 but it extends it fora longer period of time.
01:07:30.290 In addition, cyclic AMP,which is part of what’s called a second
01:07:33.910 messenger pathway, in fact,cyclic AMP is a second messenger,
01:07:37.710 is also a key player in stimulatinggrowth of the hair follicle.
01:07:41.760 Now, cyclic AMP does many different thingsin many different cell types in the body.
01:07:45.550 It really acts, as the name suggests,
01:07:47.990 as a messenger between signalsthat arrive at the surface of cells
01:07:52.310 and transmitting or conveying thosesignals to things that happen deep within
01:07:57.270 the cells, such as the turningon and off of various genes.
01:08:01.240 When you hear second messenger, don’tlet that confuse you or overwhelm you.
01:08:04.590 Just understand that the whole processof getting signals from the outside
01:08:08.550 of cells into the center of cellsand controlling gene expression,
01:08:12.790 for instance,causing a stem cell to continue to give
01:08:16.790 off daughter cells, or causing a hair cellto continue growing for longer,
01:08:20.760 that whole process is a bit likea bucket brigade of handing off water or
01:08:24.630 a bucket from one componentto the next, or along a chain.
01:08:27.840 It’s like an assembly line.
01:08:28.920 I think that’s probablythe simplest way to think about it.
01:08:31.410 For sake of this discussion,IGF-1 is known to increase the growth
01:08:35.870 of hair by extending that anagen phase,as is cyclic AMP.
01:08:41.040 Those are going to be considered
01:08:42.460 the accelerators,at least in this conversation.
01:08:45.529 The brakes on hair growth are going to be
01:08:49.340 the things that either shortenthe anagen phase or that extend
01:08:52.990 the catagen phase or this quiescent phase,which is the telogen phase.
01:08:58.050 The two major brakes on hair growth
01:09:00.550 that we want to think about are PDE,which is a phosphodiesterase,
01:09:05.569 anytime you hear -ase it’s likelyto be an enzyme, and TGF-beta-2.
01:09:10.720 This is a particular growth factor that,
01:09:13.520 somewhat counterintuitively,doesn’t stimulate growth,
01:09:15.990 it actually stimulates lack of growth,or shortens growth.
01:09:19.130 With all of that in mind,and please do also keep in mind that you
01:09:23.200 don’t need to remember all those specificterms, just understand that there are
01:09:25.910 some factors, like insulin growth factor1, that act as accelerators on growth,
01:09:30.590 and there are factorsthat act as brakes on growth.
01:09:33.640 We can start to think about why,
01:09:35.910 for instance, half of all peopleby age 50 start to lose their hair.
01:09:41.319 Well, they start to lose their hairbecause of something called androgen-
01:09:44.590 related alopecia, which,translated to English,
01:09:48.300 means testosterone and testosterone-derivative induced hair loss.
01:09:53.750 This is true in men and women.
01:09:55.800 Hearing that, you should probably bewondering the following thing:
01:09:59.720 Young men have higher levelsof testosterone than old men, right?
01:10:04.400 Well, the answer is yes,
01:10:05.630 although some older men in their 40s,50s, even 80s, maintain testosterone
01:10:10.220 levels similar to many menin their 20s, but most don’t.
01:10:13.590 It’s a downward slopestarting at about age 40.
01:10:16.990 How steep that downward slope is depends.
01:10:20.330 Women, too, have testosterone.
01:10:22.260 In fact, women have higher levelsof testosterone than they do estrogen.
01:10:26.920 That’s right.
01:10:28.250 A healthy woman has higher levelsof testosterone than she does estrogen.
01:10:32.030 However, women, on average,
01:10:34.140 have lower testosterone than most men,so they still have far more estrogen
01:10:39.300 and far less testosterone than most men,but the level of testosterone that they
01:10:43.590 have within their body is higher thanthe level of estrogen they have.
01:10:48.570 Androgens such as testosterone and its
01:10:52.140 derivatives, such as dihydrotestosterone,which will be much the topic of what we’re
01:10:57.340 getting into next,inhibit IGF-1 and cyclic AMP.
01:11:04.320 Again, androgens such asdihydrotestosterone inhibit,
01:11:08.110 prevent the action of IGF-1 and cyclicAMP, which you just learned a few moments
01:11:13.140 ago, act to extend the anagenor growth phase of hair.
01:11:16.220 Which then raises the question, well,if young people, both male and female,
01:11:21.420 have higher levels of testosterone thanthey do when they’re older,
01:11:24.950 why would people lose their hairwhen they’re older and not younger?
01:11:29.370 The answer lies in the conversionof testosterone to dihydrotestosterone.
01:11:34.630 Testosterone most people have heard of.
01:11:36.710 Dihydrotestosterone, or DHT,is made from testosterone.
01:11:41.550 There’s an enzyme called 5-alphareductase that converts testosterone
01:11:45.460 into dihydrotestosteronein both men and women.
01:11:48.920 Dihydrotestosterone bindsto the androgen receptor at five times
01:11:53.830 the affinity of testosterone,so it is the most powerful androgen
01:11:57.790 in humans, and it is responsiblefor a number of things that we all
01:12:01.750 really want and like, such asmental vigor, physical vigor, strength,
01:12:08.070 healing capacity, drive,libido, and on and on.
01:12:12.610 DHT itself is not bad.
01:12:14.720 If we take a step back and weacknowledge testosterone levels are
01:12:17.790 higher in males and females at youngerages as opposed to older,
01:12:21.070 but as they get older,there is more 5-alpha reductase activity,
01:12:24.840 which is converting moreof that testosterone
01:12:26.950 to dihydrotestosteroneand dihydrotestosterone inhibits hair
01:12:30.420 growth by reducing IGF-1 and cyclic AMP,well, then we should all be aboard why it
01:12:35.180 is that by age 50, about 50% of peopleexperience pattern hair loss.
01:12:40.630 That is androgen-dependent alopecia,
01:12:43.960 but translated to normalEnglish is pattern hair loss.
01:12:48.170 In a moment you’ll understand why somepeople lose their hair from the crown
01:12:52.300 region in the back of the head,or back and top of the head,
01:12:55.300 whereas other people lose their hairin the front of their head,
01:12:59.180 in the flanks,right on either side of the midline,
01:13:02.870 or maybe in the midlineand front altogether.
01:13:06.250 That’s because different people,depending on their genetic lineage,
01:13:10.110 have different patterns of androgenreceptors on their scalp.
01:13:14.000 The pattern of androgen receptors
01:13:15.750 that you inherit indeed doescome from your mother’s side.
01:13:19.960 This is what gave rise to the the myththat if you want to know if you’re going
01:13:23.590 to go bald or not, just lookat your mother’s father.
01:13:26.280 Doesn’t quite work that way.
01:13:27.460 In fact, if you think about the logic,you should really look at your mother’s
01:13:31.500 mother if you want to know your patternof androgen receptors on your scalp.
01:13:36.830 However, most women don’t lose as much
01:13:38.990 hair from their scalp,or they have ways of covering up the hair
01:13:42.320 loss in their scalp because their hair isjust generally longer or they’re using
01:13:45.670 other approaches, so that you never reallyget a clear picture of what the androgen-
01:13:50.110 dependent hair loss wasin your grandmother.
01:13:53.880 Now, we don’t want to go too far downthe genetics rabbit hole because,
01:13:56.960 as you know, you can’t select yourparents anyway, but if you want to know
01:14:00.500 why, for instance,I’m losing a bit of hair on either side
01:14:03.990 of the midline in the front,it almost certainly has to do
01:14:07.560 with the fact that I have a higher densityof androgen receptors there,
01:14:10.800 as opposed to, say,on the crown of my head where,
01:14:13.160 for whatever reason,my hair seems to grow thickest.
01:14:15.550 Other people lose hair on the crown,
01:14:17.450 in the back and top, but not in the front,and some people will lose it all over.
01:14:22.090 Now you understand why hair lossoccurs in certain regions of the body.
01:14:26.450 You should also understandthat the androgen receptors on the face
01:14:30.750 are also what are responsiblefor beard growth.
01:14:33.360 This is where it can get a little bittricky, but a lot of things will start
01:14:36.070 to make sense if you can understandthis and internalize this.
01:14:39.290 If you have a high density of androgen
01:14:41.380 receptors on your face,well then as your DHT levels go up
01:14:45.030 with age, you will be able to growa thicker and thicker beard.
01:14:48.380 In fact, it is rare to see someone who can
01:14:51.070 grow a thick beard in their youth,but not so much as they get older.
01:14:54.550 In fact, the reverse tends to be true.
01:14:56.480 The pattern of androgen receptors differs
01:14:58.180 between the scalpand the face and the back.
01:15:02.210 On your back you have androgen receptorsand their DHT stimulates hair growth.
01:15:06.480 If you know someone who has a very hairyback, or if you have a very hairy back,
01:15:09.520 that means you have a high densityof androgen receptors on your back.
01:15:12.380 If you have a beard and that beard is
01:15:14.560 thick, well then you have a high densityof androgen receptors on your face.
01:15:17.950 However, a high density of androgenreceptors anywhere on your scalp is going
01:15:22.110 to predispose those regions to androgen-dependent alopecia, or hair loss in those
01:15:27.260 particular regions,which is going to allow us to understand
01:15:30.670 why all of the rest of the treatmentsfor halting hair loss
01:15:34.750 and for stimulating hair growth,almost all of those center on inhibiting
01:15:40.630 either DHT directly, or 5-alpha reductase,the conversion of testosterone to DHT.
01:15:46.920 Now I’d like to discuss the ways that onecan chemically adjust certain things
01:15:50.790 within the hair growth pathway,things like IGF-1, PDE, TGF beta, etc,
01:15:57.370 in order to stimulate hairgrowth or halt hair loss.
01:16:00.520 The first thing on this list is actually
01:16:02.140 going to be pretty surprising to a numberof you, and that’s caffeine.
01:16:06.040 We all think of caffeine asa stimulant that we drink.
01:16:08.710 I certainly drink coffee in Yerba Mate,
01:16:10.880 the occasional energy drink,things of that sort.
01:16:12.910 Caffeine does many things besides
01:16:15.000 stimulate our central nervous systemand make us feel less sleepy, however.
01:16:18.640 One of the things that caffeine does isit is a fairly potent PDE inhibitor.
01:16:25.410 By being a potent PDE inhibitor,it indirectly stimulates IGF-1.
01:16:30.640 Why?
01:16:31.180 Well, because PDE can suppress IGF-1,and by ingesting caffeine,
01:16:38.090 or by applying topical caffeine ointmentor cream to the scalp,
01:16:43.840 you can suppress PDE sufficiently enoughto increase IGF-1 and increase some hair
01:16:49.140 growth, or at least maintainhair growth in that region.
01:16:52.880 This may come as a shock,
01:16:54.340 it might seem a little bit esotericor even outside the margins of typical
01:16:58.550 treatments, but head to head,topical caffeine application can be as
01:17:02.990 effective as Minoxidil applicationwithout actually lowering things like
01:17:07.300 blood pressure and potentially increasingprolactin and some of the other negative,
01:17:12.880 let’s call them negative becausethey are, side effects of Minoxidil.
01:17:16.840 Caffeine ointments, and caffeine presentin various hair treatments
01:17:21.070 and creams, etc, is starting to becomea more prominent theme out there.
01:17:25.640 I will include a reference to caffeineand its uses for offsetting hair loss.
01:17:30.240 Keep in mind that topical caffeineointments shouldn’t necessarily be applied
01:17:33.760 every single day, so this is the sort ofthing you might do three times a week.
01:17:37.160 The concentration of caffeine indifferent ointments varies tremendously.
01:17:40.420 Most of the studies of caffeine
01:17:42.320 on the stem cell niches that control hairgrowth and extension of the anagen phase
01:17:46.460 of hair growth have beenperformed in vitro in a dish.
01:17:49.380 Although there are some clinical studiesexploring this, they are not nearly as
01:17:54.000 extensive in number or duration asthe studies of Minoxidil because this
01:17:57.520 approach just hasn’tbeen around quite as long.
01:17:59.630 However, when comparing side effectsof Minoxidil, cost of Minoxidil,
01:18:03.670 comparing the efficacy of caffeineand Minoxidil,
01:18:06.220 I think caffeine as a topical treatmentfor offsetting hair loss stands as
01:18:10.630 a pretty good choice if you’re goingto start exploring this pathway.
01:18:14.160 There’s no reason to think that if youwere to try the caffeine ointment and it
01:18:17.240 didn’t work for you or you didn’t likeit for some reason or you needed to stop
01:18:20.200 it for some reason,that you couldn’t stop it safely,
01:18:22.460 because it doesn’t carry all the otherblood pressure- related effects
01:18:26.300 and prolactin emia effectsthat Minoxidil does.
01:18:29.480 If you look out there into the hairmaintenance and hair replacement
01:18:32.960 literature,and you look at thetreatments that are
01:18:35.300 being sold, don’t be surprisedto see caffeine there.
01:18:38.120 Also, don’t be surprised when I tell you
01:18:40.080 what I’m about to tell you now, which is,no, you can’t simply just drink more
01:18:43.550 caffeine in order to accomplishthe goal of offsetting hair loss.
01:18:47.480 It is true that when you ingestcaffeine, it goes systemically.
01:18:50.380 However, you have so many adenosinereceptors throughout your body.
01:18:54.120 Those adenosine receptors,and the parking of caffeine in those
01:18:57.200 adenosine receptors,is the main way in which caffeine
01:18:59.710 exerts its stimulatory effects,making you feel less sleepy.
01:19:03.960 It does that because then adenosine can’t
01:19:06.040 have its effects,which are to make you sleepy.
01:19:08.220 Well, those adenosine receptors soak up
01:19:11.130 so much of the caffeine that you wouldingest orally that very,
01:19:14.750 very little would make it to the scalpand to the hair follicles
01:19:19.160 at the concentrations that you would want,so that’s why you have to rely
01:19:22.110 on the application of these caffeineointments about three times a week.
01:19:25.960 Keep in mind that no one has really
01:19:27.710 explored the dosages of caffeinein these ointments in a systematic way.
01:19:31.400 We are still in the early stages of allthis, but I do think it’s important
01:19:34.730 to mention caffeine because of the lowerincidence of side effects,
01:19:38.080 at least reported side effects,and the general safety margins,
01:19:40.910 and the head to head essentiallycomparable efficacy with Minoxidil
01:19:44.600 because Minoxidil hasa bunch of other issues.
01:19:46.870 Now keep in mind that both Minoxidiland caffeine are generally used as
01:19:51.110 a preventative for reducinghair loss over time.
01:19:55.220 They are not expected,and they do not, as far- as far as we
01:19:58.750 know, create new hair growthto any sufficient degree.
01:20:03.120 If any of you have used caffeine,ointments or minoxidil and observed new
01:20:06.680 hair growth that was robust,please put that in the comment section.
01:20:09.840 I’d be curious about those experiences,but as far as I know
01:20:12.600 and from the clinical literature that Iread, there’s no examples of that.
01:20:16.340 One other point about caffeine.
01:20:18.030 It does appear that caffeine can not onlyindirectly stimulate IGF-1 and the antigen
01:20:22.990 phase of hair cell growth by wayof reducing PD and TGF beta.
01:20:27.220 But it also seems to reduce apoptosis
01:20:30.220 which is naturally occurring celldeath of that stem cell niche.
01:20:33.560 We’ve been talking a lot aboutthe antigen or growth phase of hair.
01:20:36.200 We also talked about the catagen or
01:20:37.990 the recession of that hairfrom the inside out.
01:20:40.320 But remember that third phase,
01:20:41.600 the telogen phase, where that whole bulbdown at the bottom, the bulge,
01:20:45.080 as it’s called,gets pinched off and the whole thing dies
01:20:47.480 and takes the stem cellsoff to the grave with it.
01:20:49.710 It appears that caffeine can offsetthe death of that niche and potentially
01:20:54.180 maintain the stem cell population longer,making caffeine a really good choice
01:20:58.870 to think about in conjunctionwith the various chemical treatments
01:21:02.380 aimed at directly attacking the DHTpathway that we’ll talk about next.
01:21:06.710 So there’s one very direct wayto increase hair growth and maintain
01:21:10.460 the hair that you have on your head,and that’s to increase IGF-1.
01:21:14.920 That can be accomplished throughprescription drugs such as growth hormone
01:21:19.590 and things that stimulate the releaseof growth hormone and IGF-1.
01:21:23.800 Keep in mind, growth hormone is released
01:21:25.500 from the anterior pituitary duringthe first hours of sleep,
01:21:28.920 especially when you haven’t eatenanything for the two hours prior
01:21:31.670 to sleep, and especially whenyou get regular bedtimes.
01:21:35.630 Yes, this is a real thing.
01:21:37.340 If you are going to sleep at variablebedtimes, especially if you go to sleep
01:21:41.500 much later than your usual habitualbedtime, you will miss that growth
01:21:45.180 hormone pulse that normally occursin the first 2-3 hours of sleep.
01:21:49.480 This does not mean that you need to be
01:21:50.760 neurotic about getting to sleepat the exact same time every night.
01:21:53.280 There’s probably a plus or minus 30-
01:21:54.910 minute window,and it doesn’t mean that you can’t stay
01:21:58.070 out late or have a bad night’s sleepevery once in a while or get woken up.
01:22:02.040 Your hair isn’t going to fall out.
01:22:03.750 My dad’s story notwithstanding,
01:22:06.200 your hair isn’t going to allfallout because of that.
01:22:08.280 But you do want to try and get
01:22:09.720 that natural growthhormone release each night.
01:22:11.950 And as I mentioned,
01:22:13.380 there are prescription approachesand those are growth hormone itself.
01:22:18.090 Things like sermorelin, which isa peptide that increases growth hormone.
01:22:22.140 It’s actually a secreted dog.
01:22:23.950 It causes the secretion of growthhormone and thereby increases in IGF-1.
01:22:28.630 This is well documented.
01:22:29.870 Both growth hormone and IGF-1, as Imentioned, are available by prescription.
01:22:34.140 They are not without their side effects.
01:22:37.090 They do cause growth of all tissues.
01:22:38.990 They do increase height in children,They increase bone mass and density.
01:22:42.910 They can increase mainly fat loss,not so much muscle size,
01:22:46.380 but they can increase leanness and theyincrease hair growth,
01:22:49.720 They can increase turnover of skin,they can make skin look more youthful.
01:22:52.840 All these things sound wonderful.
01:22:54.340 And yet they also have problems because
01:22:57.480 they can increase growth of small tumorsthat normally might be eliminated.
01:23:00.990 So there is an increased cancer risk
01:23:03.030 with growth hormone treatments and IGF-1or anything that increases IGF-1 such as
01:23:08.760 sermorelin or ipamorelin, any of thepeptides that you hear about nowadays.
01:23:12.670 That said, a number of people are usingsermorelin as an indirect way to increase
01:23:16.840 IGF-1 and therebyto increase hair growth.
01:23:19.220 It does seem to be fairly effectivein doing that, especially when done
01:23:23.080 in conjunction with othertreatments that we’ll talk about.
01:23:25.240 But keep in mind, these are prescriptiondrugs and they do carry their own risks.
01:23:29.140 The other thing about stimulatingthe natural production of IGF-1 is that,
01:23:33.030 as its name suggests,insulin growth factor one,
01:23:35.790 it is insulin dependent in many ways,if not for its secretion,
01:23:39.710 then for its action at the hairfollicle and stem cell.
01:23:43.400 So one of the things you really wantto pay attention to is to avoid being
01:23:46.790 insulin resistant, or rather youwant to try to be insulin sensitive.
01:23:51.600 So if you’re carrying a lot of excess
01:23:52.950 body fat, if you’re obese or if you havetype two diabetes,
01:23:56.520 meaning your insulin resistant,you’re going to want to deal with that.
01:23:59.200 There are a number of prescriptiontreatments to deal with that nowadays.
01:24:01.830 People are very excited about all the GLPone agonists, but in addition to that,
01:24:05.880 regular cardiovascular exerciseand resistance exercise,
01:24:09.260 making sure that your body fat percentageis not in excess of where it needs to be.
01:24:14.760 Everyone has a slightly different idea
01:24:16.760 of where it needs to be,both cosmetically and for health.
01:24:19.200 So that’s a conversation between youand your doctor and you and you frankly.
01:24:22.950 But you want to avoid being insulinresistant because being insulin resistant
01:24:27.990 and being obese canindeed lead to hair loss.
01:24:30.840 There are many people out there who are
01:24:31.990 not obese who nonetheless are experiencinghair thinning and hair loss because they
01:24:36.790 are insulin resistant by wayof reduced IGF-1 activity.
01:24:40.560 There are a few supplements.So these are over-the-counter
01:24:42.870 supplements such as myo-i nositol,taken at dosages of about 900 milligrams
01:24:47.220 before sleep, which by the way,can also assist in sleep or things like
01:24:51.420 berberine or metformin, which areknown to improve insulin sensitivity.
01:24:56.220 Each and every one of these has its ownprofile of positive and negative effects.
01:25:00.790 The lowest number of side effects isassociated with 900 milligram myo-i
01:25:06.040 nositol taken about 30 minutes beforesleep, mostly because it can make people
01:25:09.340 a little bit drowsyand it does aid sleep in some really
01:25:12.590 great ways,but really exercise and maintaining
01:25:15.480 a healthy nutritional programare also going to be key.
01:25:18.220 You just can’t discard those.
01:25:19.680 Berberine, which is a substance made
01:25:21.480 from tree bark is sometimescalled the poor man’s metformin.
01:25:24.220 Metformin being the equally effectiveprescription version of berberine.
01:25:29.240 Or put differently,
01:25:30.180 berberine is the non-prescription butequally effective version of metformin.
01:25:34.630 Keep in mind that both berberine
01:25:36.420 and metformin dramaticallyreduce blood sugar levels.
01:25:39.520 And so if you’re not going to take them
01:25:40.680 with carbohydrates, it can leadto some feelings of discomfort.
01:25:43.440 That’s why I’m not a fan of them.
01:25:44.830 But if your goal is to really improveinsulin sensitivity,
01:25:48.070 they are considered very potent toolson the list of things that can do that.
01:25:52.320 The other thing that’s really importantfor maintaining proper hair growth,
01:25:55.140 this antigen phase,is that you need sufficient iron.
01:25:58.130 This is because iron and ferritin play
01:26:01.140 a key role in the cell growth pathwaysthat go from the stem cells
01:26:05.830 to the stimulation of keratinwithin the hair itself.
01:26:08.760 I don’t have time to go into this
01:26:09.790 pathway in a lot of detail, but you canhave your blood levels of iron measured.
01:26:14.400 This turns out to be pretty important
01:26:15.800 because you don’t just want to startpopping iron supplements because too much
01:26:18.790 iron can be toxic,too little means you’re anemic.
01:26:21.640 For women, the levels of iron that youwant are somewhere between 25 and 100.
01:26:27.380 And for men, somewhere between 30 and 150.
01:26:30.250 Fortunately, the tests or the bloodtests for iron are usually a very
01:26:34.340 inexpensive add to yourcurrent blood panel.
01:26:37.320 So if you’re going in for a blood panel
01:26:38.710 for LDL, HDL, typical things,or if you’re doing the more elaborate
01:26:42.640 hormone testing,which I do recommend people do if they
01:26:45.200 can afford it or if their insurance coversit, do ask for an iron test as well.
01:26:48.840 And if your iron is low,you may need to supplement your iron.
01:26:51.240 If your iron is too high,that’s not good either.
01:26:53.670 But iron plays a key role in the antigen
01:26:56.400 phase of hair growth, so you want to makesure you at least have sufficient iron.
01:27:00.360 And if you don’t, you want to make sure
01:27:01.550 that you’re getting it from nutritionand or supplementation.
01:27:04.840 Earlier, we were talkingabout dihydrotestosterone.
01:27:07.340 Dihydrotestosterone,
01:27:08.550 just to jog your memory,is a form of testosterone that combine
01:27:12.300 the androgen receptor at five timesthe affinity of regular testosterone.
01:27:17.570 Both men and women have a lotof testosterone relative to estrogen.
01:27:21.520 It just so happens that men tend to havemore testosterone than women do overall.
01:27:25.530 But both men and women, as they age,convert more of the testosterone they
01:27:30.460 have to dihydrotestosteroneand dihydrotestosterone does two things
01:27:35.600 that are bad for hairmaintenance and hair growth.
01:27:37.990 First of all, it shortens the antigenphase, that growth phase.
01:27:42.200 Whatever hair is going to grow is goingto occur over a shorter period of time.
01:27:46.110 Second of all, because of the presence
01:27:48.830 of androgen receptors on the stem cellniche area and around it,
01:27:53.630 it actually miniaturize the follicleand the stem cell niche.
01:27:57.480 In other words, it makes the populationof cells that give rise to more hair
01:28:01.070 protein smaller and caneliminate it altogether.
01:28:04.790 And that is why anything that reduces 5-
01:28:07.300 alpha reductase is going to reduce DHT,is going to maintain or extend the growth
01:28:13.420 phase, the antigen phase of hair growthand is going to offset or prevent some
01:28:18.150 of the telogen phase, the pinching offand the removal of that stem cell niche.
01:28:23.400 Now, one substance that we know can
01:28:25.110 inhibit 5-alpha reductase,although it does it pretty weakly is saw
01:28:29.500 palmetto, which is an extractof the saw palmetto berry.
01:28:32.640 To be honest, I don’t know howthis was initially discovered.
01:28:35.240 If anyone knows, please putit in the show note captions.
01:28:37.460 When I looked online I found a bunchof conflicting stories about who was
01:28:41.380 the first person to start extracting theextract of the saw palmetto berries.
01:28:46.150 So I have no ideawhich one of those is true.
01:28:48.460 Maybe somebody can tell me.
01:28:50.360 The good thing about saw palmetto
01:28:51.790 treatment is that it is known to havevery few, if any, side effects.
01:28:55.760 There might be some side effects
01:28:57.030 in about 1% of people, but it’s notassociated with a lot of side effects.
01:29:01.570 It’s also known that when taken at about
01:29:04.240 300 milligrams per day and here itdoesn’t have to be that strict.
01:29:07.420 Most of the studies that I exploredinvolved taking anywhere from 200-
01:29:12.080 500 milligrams of saw palmetto,but most of them focused on about
01:29:15.230 300 milligrams of saw palmetto per day,divided into two or three doses.
01:29:19.280 Why?Well, it has a relatively short half-life,
01:29:22.280 meaning it’s going to get clearedfrom the bloodstream and more importantly,
01:29:25.040 its biological action isgoing to be very short-lived.
01:29:27.420 So if you can get a hold of 50 or 100-milligram capsules or tablets
01:29:31.910 of saw palmetto and divide those up,take them in the morning,
01:29:35.720 afternoon and evening,or even just in the morning and evening
01:29:38.030 to achieve a total of about300 milligrams per day.
01:29:41.210 That’s going to very likely help you holdon to some of the hair that you would
01:29:46.550 have otherwise lost,maybe even grow some new hair.
01:29:49.420 And I say maybe give you some new hairgrowth because saw palmetto is not
01:29:53.380 known to be a particularly robusttreatment for the reversal of hair loss.
01:29:57.680 It’s known to have some effect,
01:29:59.190 but it’s generally taken in conjunctionwith a bunch of other things.
01:30:02.990 And so it’s really hard to tease outjust what amount of hair growth or
01:30:07.650 prevention of hair loss is dueto saw palmetto specifically.
01:30:10.840 But I mention it here because
01:30:11.990 the mechanism of action is logicaland fairly well-known,
01:30:15.270 which is this week effect in reducing 5-alpha reductase and thereby reducing DHT.
01:30:20.840 So again, because it has relatively low
01:30:22.710 side effects, even though it’s not supereffective and because it’s fairly low
01:30:26.750 cost and it’s available over the counter,I felt it was important to include.
01:30:31.920 Now, as soon as people hear things like
01:30:33.880 saw palmetto berry, they’re probably alsothinking, “Oh boy,
01:30:36.440 here comes all the herbals.” Now keepin mind that there are some herbal
01:30:39.950 compounds that have prettyrobust biological effects.
01:30:42.990 And we talked before in our optimizingtestosterone episodes about things like
01:30:47.840 Tongkat Ali and Fadogia agrestis,which taken incorrect dosages
01:30:52.000 and in the correct way,can be pretty potent for increasing
01:30:54.340 luteinizing hormone and freetestosterone that can have huge effects.
01:30:58.040 It’s not like taking exogenous anabolicsteroids, but they can have real effects.
01:31:01.950 And so herbal compounds can be potent.
01:31:04.670 However, I do acknowledge that there isa vast market out there of herbal
01:31:08.710 compounds and plant-basedcompounds that people are arguing.
01:31:12.300 Mostly the people who sell them arearguing can increase hair growth.
01:31:16.040 There are some decentstudies of these things.
01:31:18.230 The hard part about studying these herbal
01:31:20.500 compounds and these plant-derivedcompounds for increasing hair growth is
01:31:24.460 that they are often takenin combination with one another.
01:31:27.420 In fact, most of the hair growth
01:31:29.750 supplements that involve these herbalcompounds and plant compounds include 5
01:31:34.910 or 10, sometimes evenmore things altogether.
01:31:37.400 So teasing out which ones are effective
01:31:39.150 and which dosages are effectiveis nearly impossible.
01:31:41.880 There are just too many variables.
01:31:43.570 You will hear, for instance,that green tea extract, Reishi Mushroom,
01:31:47.590 pumpkin oil, zinc, curcumin, allof these things can increase hair growth.
01:31:53.880 Perhaps the only thing on that listthat makes logical sense with respect
01:31:57.070 to the biochemistry is that curcumin isknown to, in some people,
01:32:01.570 be a potent inhibitor of 5-alpha reductaseand DHD so much so that I can personally
01:32:06.590 say for me I once took curcumin,turmeric, it’s also called in high dosage.
01:32:12.830 This is about a gram to 2 gram capsulesand I felt absolutely terrible.
01:32:17.130 I mean, just dreadful.
01:32:18.280 I don’t care if it allowed me to keep
01:32:19.670 my hair forever, I would ratherlose all my hair three times over.
01:32:23.800 I guess that means itwould have grown back.
01:32:25.270 I’d rather lose all my hair.
01:32:26.910 Let’s just put it that way
01:32:28.960 than ever take curcumin orturmeric in high dosages again.
01:32:32.160 In saying that, I know that many peopletake turmeric and curcumin and really like
01:32:35.670 its anti-inflammatory propertiesand don’t experience any side effects.
01:32:39.460 I just happen to be particularly sensitiveto curcumin by way of this DHT pathway.
01:32:44.160 I know this by way of blood work, so I’mnever going to hear that stuff again.
01:32:47.230 That said, a lot of these herbal compounds
01:32:50.150 and cocktails probably will have someminor marginal,
01:32:55.800 infinitesimally small,somewhere in that range effect
01:32:58.550 on maintaining hair growth orin stimulating new hair growth.
01:33:02.920 It’s just that there really aren’t
01:33:04.200 clinical studiesto support any one of them.
01:33:06.040 And that’s why I singled out saw palmettoas one of the few
01:33:08.870 for which the biochemical pathwayof inhibiting 5-alpha reductase
01:33:12.110 and the low incidence of side effectsand the fact that many people have used it
01:33:16.230 with some degree of successmakes it a standalone.
01:33:19.630 I wouldn’t say recommendation,but a consideration.
01:33:22.380 Another commonly discussed and usecommercial compound for offsetting hair
01:33:26.910 loss and stimulating hairgrowth is ketoconazole.
01:33:29.990 Sometimes this is known as Nizoral whereNizoral is the brand name of a shampoo.
01:33:35.270 Ketoconazole is an antifungal that was
01:33:38.150 initially developed to treatdandruff and severe psoriasis.
01:33:42.370 Ketoconazole has been shown to beeffective in increasing hair number.
01:33:46.640 It’s also been shown to be effective
01:33:48.460 in increasing hair diameter,which is somewhat surprising because one
01:33:52.230 of the common side effects of ketoconazoleis drying, thinning and brittle hair.
01:33:57.400 So what’s going on there isa little unclear.
01:33:59.600 We’ll return to that in a moment.
01:34:01.090 The mechanism of actionfor ketoconazole is pretty interesting.
01:34:04.320 Remember earlier we were talking about
01:34:05.670 the sebaceous gland and the productionof sebum, that oily stuff
01:34:09.330 whose very name seems to evokedisgust in certain people.
01:34:12.270 Well, ketoconazole can disrupt some
01:34:14.550 of the fungal growth that frankly,we all have on our scalp all the time.
01:34:18.790 I know this is a surprise to many of you,but you are constantly bombarded
01:34:22.790 with viruses, bacteriaand funguses all the time.
01:34:26.760 But we managed to battle those off
01:34:28.280 with our immune system,either by physical barriers such as
01:34:30.630 an oil barrier like the sebumor through antimicrobial action.
01:34:35.570 Chemical approaches our immune system,the sebum, etc,
01:34:38.840 ketoconazole acts as an antifungalthat in some way seems to reinforce
01:34:43.950 the properties of sebum at keepingout other fungal infections.
01:34:48.110 And the net effect, at least as far aswe know, is a mild reduction in DHT.
01:34:53.380 Now exactly how thishappens isn’t really clear.
01:34:55.990 What is clear is that the use
01:34:58.230 of ketoconazole shampoo is2-4 times per week with a scalp contact
01:35:04.270 time of about 3-5 minutes has been shownto give about an 80% response rate
01:35:09.950 of maintaining hairthat would otherwise be lost.
01:35:12.460 So that’s pretty dramatic, 80%.
01:35:14.400 What is less clear is whether or not
01:35:15.990 ketoconazole shampoo can actuallystimulate new hair growth.
01:35:19.440 But as you’re probably startingto realize,
01:35:21.670 this is always a bit of a tough thingto disentangle maintenance of hair
01:35:25.480 that you would have lostversus new hair growth.
01:35:27.690 Certainly,that’s an easy thing to disambiguate if
01:35:30.270 you have a patch of scalp where there isabsolutely no hair,
01:35:33.490 these so-called dead zones that youcan resurrect with certain treatments.
01:35:38.110 But what about areas of yourscalp where hair is thinning?
01:35:41.320 So, for instance, on the top of your head,
01:35:43.420 this is where many women will firstexperience pattern, hair loss.
01:35:47.000 Alopecia is right at their midline,
01:35:50.360 especially if theyhave a part right there.
01:35:51.920 They’ll start to notice that under very
01:35:53.280 bright light,fluorescent lights in particular,
01:35:55.190 they’ll notice a thinning of theirhair there or in the forehead region.
01:35:59.370 They’ll start using ketoconazole shampoo.
01:36:01.960 Again, the typical recommendation is 2-4times per week with a scalp contact time
01:36:06.520 of 3-5 minutes and really rubbingit in and then rinsing it out.
01:36:09.520 You don’t need to be super vigorous,but you want to make sure that it gets
01:36:12.040 down into the follicle and aroundthe follicles, not just sitting on top
01:36:15.550 of the hair,which is going to be especially
01:36:18.150 important for people who havelong hair to really massage it in.
01:36:21.490 Well, they will experience a growthof hair in that particular region
01:36:25.460 that almost certainly were dueto miniaturization of the hair follicle
01:36:29.150 and reduction of the total populationof stem cells in that follicle as opposed
01:36:33.550 to complete lossof the stem cell population.
01:36:36.080 The reason we say this is that there’s noreason to think that ketoconazole can
01:36:38.990 actually stimulateIGF-1 or activate growth itself.
01:36:42.830 It’s probably offsetting someof the reductions in the antigen phase
01:36:47.190 and some of the exacerbationof the telogen phase.
01:36:49.960 Now, if you decide to use ketoconazole as
01:36:52.040 an approach to offsetting hair loss,it’s very important that you get a hold
01:36:55.380 of a shampoo that’s at least 2%concentration of ketoconazole.
01:36:59.400 This is important because a lotof the ones that are available out there,
01:37:02.870 especially online,are going to be 1% or lower.
01:37:05.950 So you want to try and obtaina ketoconazole shampoo of 2% or higher
01:37:10.300 concentration of ketoconazole becauseit has other things in it, of course.
01:37:14.240 I should mention that there are occasionalside effects with ketoconazole.
01:37:17.520 The rates of side effects from the metaanalyzes and reviews that I read were
01:37:21.270 somewhere between 1% and 8% of peoplewill experience some side effects,
01:37:25.030 but those side effectstend to be pretty mild.
01:37:27.340 Things like irritation of the scalp,
01:37:29.570 things like thinning and brittlenessof the hair that sometimes can be offset
01:37:33.680 by using shampoos that containthings like biotin.
01:37:36.200 I know many people are probably curious
01:37:37.710 about biotin, which is a protein that canbe incorporated into the keratin.
01:37:42.490 Whether or not different biotin enrichedshampoos can really enhance the total
01:37:47.230 amount of biotin that gets incorporatedinto the hair isn’t clear,
01:37:50.710 but it is clear that having sufficientbiotin around is important.
01:37:54.030 So if you get a little bit extrafrom your shampoo,
01:37:56.560 you can imagine how that would “tapoff” the amount of biotin in that hair.
01:38:00.400 And there are people out there saying
01:38:01.800 that by biotin-enriched shampooshave done wonders for them.
01:38:04.750 Who knows?I’m not going to dispute their experience.
01:38:08.170 So if you’re going to use ketoconazole,
01:38:10.300 keep in mind that the more typical brandnames that are out there,
01:38:14.550 you know which ones they are,oftentimes don’t have 2% or if they do
01:38:19.710 have 2%, they can be very dryingand lead to brittle hair.
01:38:23.570 There are newer and now fortunately,
01:38:26.710 a greater variety of ketoconazolecontaining shampoos.
01:38:29.910 We as a podcast and I don’t have any
01:38:32.230 affiliation to any of these,but I will provide a links to a couple
01:38:35.630 of the more prominent ones that are knownto have 2% concentration of ketoconazole,
01:38:40.200 as well as some other things in them knownto offset some of that dryness
01:38:43.340 and brittleness that ketoconazoleshampoos can trigger.
01:38:46.730 So by now, I think it will be abundantly
01:38:49.110 clear why inhibiting 5-alpha reductaseand thereby reducing DHT should increase
01:38:55.110 hair growth because of the negativeimpact that DHT has on the hair follicle.
01:39:01.770 The major player in this whole story
01:39:04.420 around inhibiting 5-alpha reductaseand reducing DHT to maintain or increase
01:39:09.830 hair growth is going to be finasterideand its close cousin, dutasteride.
01:39:15.130 Finasteride is effective in reducing DHTbecause of its actions in reducing
01:39:19.710 the type two isoenzyme orisoform of 5-alpha reductase.
01:39:24.440 It turns out there’s three different
01:39:25.830 isoforms or what are sometimes calledisoenzymes of 5-alpha reductase.
01:39:29.720 This is getting prettyfar down in the weeds.
01:39:31.840 What I think most of you just need
01:39:33.190 to know is that finasteride reduces DHT,that’s the net product of finasteride
01:39:38.500 and in doing so, it can increasehair count by as much as 20%.
01:39:42.200 Pretty remarkable if you think about it.
01:39:44.090 In addition, finasteride treatment doneproperly, which we’ll define in a moment,
01:39:49.920 can reduce hair loss in 90%of all people that take it.
01:39:54.410 That is near staggering.
01:39:56.560 I mean, there aren’t many pharmaceuticals
01:39:57.870 Out there that have thatefficacy, really dramatic.
01:40:00.750 In addition, it’s known to increase hairthickness by about 20- 30% overall,
01:40:05.750 so not just create new growth of hairs,and thicker hairs, but whatever hair you
01:40:10.600 do happen to have on your head,it can further thicken those.
01:40:13.410 The finasteride story is one,I think, of general success.
01:40:18.550 It really seems to improve hair growth,
01:40:20.790 and help you hold on tothe hair that you have.
01:40:23.570 The issue with finasteride is twofold.
01:40:25.770 First of all, it is known to have somepretty significant side effects if it’s
01:40:29.750 not dosed properly,and in particular populations of people.
01:40:34.150 This is because there is a wide variation
01:40:37.550 in the amount of the differentIsozymes that people make.
01:40:42.320 This is why I brought upthe Isozymes earlier.
01:40:44.500 Some people make more of Isozyme oneand three, some people make more of
01:40:49.270 Isozyme two and three,and every variation thereof.
01:40:53.270 When people take finasteride,some people are very strong responders,
01:40:57.870 and they achieve really effectivehair regrowth and maintenance of hair.
01:41:01.710 Other people less effective,although still pretty impressive.
01:41:05.150 But the catalog of side effects
01:41:07.270 that people experienceat a given dose, varies widely.
01:41:10.070 There’s a lot of trialand error that has to take place.
01:41:13.330 Also, I should point out that finasteridecomes in two major forms.
01:41:17.190 There’s an oral formand there’s a topical form.
01:41:20.110 This is not unlike ourdiscussion of minoxidil earlier.
01:41:23.730 Topical finasteride is typically taken
01:41:26.550 in 1% solution or ointment and rubbedinto the head, sometimes it’s now also
01:41:31.750 incorporated into shampoos,but typically it’s put into a solution
01:41:35.630 that people rub into their head,and it is thought that the 1% solutions
01:41:39.590 are equivalent to one mgof systemic finasteride.
01:41:43.960 Now we need to take a step back and ask
01:41:45.680 why was finasteridedeveloped in the first place?
01:41:47.830 Well, finasteride, as a fairly potent five
01:41:50.300 alpha reductase inhibitor,it’s great at lowering DHT.
01:41:53.770 It was developed for treatment
01:41:55.420 of prostate enlargement and variousissues of the prostate that are
01:41:58.950 associated with elevated DHTthat occurs with age.
01:42:01.640 The topical finasteride were designed
01:42:03.500 with the hope that the finasteride wouldmake it into the hair follicle,
01:42:07.460 and would inhibit DHT there and allowfor more growth of the hair,
01:42:11.080 which apparently it does,but not make it into the systemic
01:42:13.640 circulation,or at least not at concentrations
01:42:15.550 sufficient enough to cause as manyside effects as with the oral dosing.
01:42:19.380 Now, the problem is, it doesmake it into systemic circulation.
01:42:23.730 The issue is also,
01:42:25.380 that topical application of finasterideis harder to dose than oral finasteride.
01:42:30.920 I’m not saying you should be taking oralrather than topical finasteride,
01:42:34.300 but keep in mind that the dosagesof finasteride that have been shown to be
01:42:38.270 effective for inducing hair growth,cover an enormous range.
01:42:41.750 As low as 0.01mg per day and as high as
01:42:46.030 five mg per day, which isa just staggering range.
01:42:50.960 Now, when trying to simplify the problem
01:42:52.950 of how much finasteride to take,either by way of oral tablet,
01:42:56.380 or by way of topical solution,we can get a bit of leverage on this
01:43:01.190 by thinking about how much DHTreduction occurs as a function of dose.
01:43:05.590 There, finasteride shows this really
01:43:08.300 interesting, what’s calledlogarithmic distribution.
01:43:11.340 What it means is that,
01:43:12.750 for a dosage of 0.01mg of finasteride,you’re going to achieve approximately
01:43:18.710 50% reduction in DHT,and that’s systemic DHT,
01:43:22.790 so this is a blood draw measuring yourDHT, then taking 0.01mg of finasteride.
01:43:28.300 Again, 0.01, very low dose of finasteride,repeated a couple of weeks,
01:43:33.670 measure people’s DHT in their blood again,and you see that it’s reduced by 50%.
01:43:38.570 However, at increasing dosages of 0.2mg,one mg, five mg of oral finasteride per
01:43:48.380 day, over the same period of time,the increase or I should say
01:43:53.340 the reduction in dihydrotestosterone,doesn’t increase linearly.
01:43:57.230 It’s not that you go from 50%-6 0%-75%-
01:44:00.690 100% with each increasing dose,it tapers off, it flattens out.
01:44:04.880 It tends to increase a little bit,
01:44:06.110 but it’s a gradual slope increasingas you head from 0.2mg out to five mg.
01:44:12.750 What this means is that giventhat reducing DHT can cause various side
01:44:18.870 effects, sexual side effects,reductions in either sexual function or
01:44:23.420 sexual drive, as well as overall driveand motivation,
01:44:26.950 sometimes even some depressive symptomsthat everything points to taking
01:44:32.190 the lowest effective dose of finasterideand starting with a very low dose
01:44:36.550 of finasteride because low dosesof finasteride, even at that 0.01mg taken
01:44:42.340 orally daily,are already leading to a 50% reduction
01:44:47.340 in dihydrotestosterone and thereby takenfor a long enough period of time,
01:44:51.340 should offset hair lossand stimulate hair growth.
01:44:54.090 One of the problems, however,
01:44:55.630 is that people will start takingfinasteride at a low dose 0.1mg or 0.2mg,
01:45:00.630 maybe even 0.01mg,and there will be a reduction in their
01:45:05.230 DHT, but because of the long durationof that antigen phase,
01:45:09.750 they don’t see a lot of change in hairgrowth in the first month or even two
01:45:14.000 months, and so what they end up doing isincreasing their dosage and then they
01:45:17.420 start to see hair growth, but then theystart to experience more side effects.
01:45:21.320 Now the side effects of oral finasteride
01:45:23.230 are serious enough and common enoughin people that take finasteride
01:45:26.640 that the topical solutions were developed,but there are two one needs to exercise
01:45:30.340 caution because if we are goingto translate between topical finasteride
01:45:34.590 and oral finasteride,with the understanding that topical
01:45:37.550 finasteride can actually make itinto the systemic circulation,
01:45:40.720 we need to look at what’s been shownin clinical studies,
01:45:43.460 which is that for instance,taking one ml of 0.25% finasteride applied
01:45:48.830 to the scalp, this is a very typicalrecommendation, translates to the same
01:45:53.870 thing that would be achievedwith 2.5mg of oral finasteride.
01:45:59.680 When I say translates to the same thing,
01:46:01.420 what I mean is it leads to the sameconcentrations in the blood.
01:46:05.000 Now consider that 0.2mg, 0.2mg
01:46:10.690 of finasteride in the blood is knownto be effective in generating new hair
01:46:14.750 growth and maintaining hair that onealready has when they start the treatment.
01:46:18.690 If you think that the topical
01:46:20.990 finasterides are actually creating loweroverall systemic concentrations
01:46:26.460 of finasteride, that isnot necessarily the case.
01:46:29.270 Again, one ml of topical finasteride
01:46:31.910 at 0.25% leads to a 2.5mg concentrationin the blood, when the effective dose
01:46:38.710 within the bloodstream by taking it orallyas a pill is 0.2mg.
01:46:44.360 That might not seem like a big dealto you, although it is a big deal, right?
01:46:47.950 We’re talking 2.5mg versus 0.2,
01:46:51.050 but it is a huge deal when you considerthat the side effects of finasteride
01:46:55.790 increase as you increase the concentrationof finasteride in the bloodstream.
01:46:59.920 Where does this leave us?
01:47:01.500 Should people who are interestedin taking finasteride take the oral form
01:47:05.630 at low dose or take the topical formand simply try and apply it less often or
01:47:10.760 guess at what their systemicconcentration of finasteride is.
01:47:13.560 Well, it’s going to varyfrom person to person.
01:47:15.480 Some people are very sensitiveto finasteride and not in the good sense.
01:47:18.960 The side effects just really show upquickly and they tend to be dramatic.
01:47:22.380 Other people, not so much.
01:47:25.040 The dosage recommendations that I wasable to arrive at based on the clinical
01:47:28.790 studies and frankly in discussionwith some doctors who prescribe
01:47:32.870 finasteride were the following: 0.5mgto one mg of finasteride as a tablet per
01:47:39.950 day seems to be an effective and prettysafe starting place for most people.
01:47:46.040 Now some people will find that even
01:47:47.560 that 0.5mg dosage is just going to causeside effects that are not going to work
01:47:51.500 for them, and they’re going to either haveto reduce their dosage of finasteride or
01:47:56.190 move to the topical or maybe ceasetaking finasteride altogether.
01:47:59.630 But for many people out there,that’s going to be pretty well tolerated.
01:48:03.800 The key thing here is that one is goingto have to wait some period of time
01:48:07.400 to see whether or notany hair growth occurs.
01:48:09.460 It is a naive and frankly foolishapproach based on what we know about
01:48:13.950 the duration of that antigen phaseof the hair to do one of these
01:48:17.720 treatments, wait a week or twoand then decide to up your dose.
01:48:20.750 Now, it is not foolish to reduce your dose
01:48:23.030 if you’re experiencing bad side effects,but to simply increase your dose because
01:48:27.240 you’re not getting results quickly enough,that’s not going to be the best approach.
01:48:30.800 I really encourage people who are goingto explore the finasteride route,
01:48:34.030 to think of this as a long-term projectand to really ratchet up slowly if at all,
01:48:38.720 starting initially with a low dose takenfor a long period of time,
01:48:41.500 maybe even as long as 25 weeks beforeconsidering going up any further.
01:48:46.080 Certainly, as I mentioned before,if you need to go down further,
01:48:49.170 that’s not going to be a problem,at least not in terms of reducing side
01:48:53.640 effects, you’re not going to getadditional hair growth,
01:48:55.360 but you’re certainly not going to increaseyour side effects if you reduce your dose.
01:48:58.960 However, I will talk a little bit laterabout post-finasteride syndrome,
01:49:02.160 which is something that’s gettingincreasing attention nowadays.
01:49:04.480 That’s something that occurs after
01:49:06.000 people have taken finasteridefor an extended period of time.
01:49:08.920 Now some of you have perhaps heardand I’ll just tell you right here,
01:49:11.950 that the topical forms of finasteride areassociated with far less side effects.
01:49:17.300 Now that might come as surprising giventhat topical application of finasteride
01:49:21.380 can lead to systemicdistribution of finasteride.
01:49:23.870 But the numbers that are out there right
01:49:25.950 now, it’s that topical finasteride isassociated with 30-50% fewer side effects
01:49:31.190 or 30-5 0% less severe sideeffects than oral finasteride.
01:49:36.160 There are several thingsprobably responsible for that.
01:49:38.440 One is that people tend to ratchet up
01:49:40.040 their dose of oralfinasteride pretty quickly.
01:49:42.070 But keep in mind that the effective doseof finasteride in the blood is 0.2mg.
01:49:48.050 Earlier I said the typical topicalfinasteride solutions are 0.25%. People
01:49:53.030 are taking one ml of it,that equates to 2.5mg,
01:49:55.990 and so it seems like a massive overdosingbut here’s the discrepancy and here’s
01:50:00.630 where we can arrive at somereasonable recommendations.
01:50:04.250 If you decide that finasteride isright for you, you get a prescription.
01:50:08.520 I would hope that you’re monitoring yourDHT levels and other hormone levels
01:50:11.910 that would be ideal,and working with a doctor, please.
01:50:16.000 0.5mg to one mg per day of oral
01:50:19.630 finasteride seems to bethe best starting place.
01:50:24.290 For topical finasteride.
01:50:26.290 It’s going to be that one ml of 0.25%that we talked about earlier,
01:50:32.160 but that’s taken only one time per week,and you can fully expect that right after
01:50:36.000 the application you will have higherlevels of finasteride in your bloodstream,
01:50:39.750 and therefore lower levels of DHTand that will alter across the week.
01:50:44.280 Most people are not going to be able
01:50:45.870 to measure their DHT on a dayby day or even weekly basis.
01:50:48.990 It’s just too expensiveand labor intensive.
01:50:51.560 But I think those dosing regimens ought
01:50:53.500 to get people into more or less the samecategory of optimizing hair maintenance
01:50:57.910 and hair growth while minimizingfinasteride side effects.
01:51:01.150 One point about finasteride taken eitheralone or in combination is that in recent
01:51:07.270 years, really in the last five or soyears, there’s been increasing discussion
01:51:11.990 about so-called post-finasteride syndrome.
01:51:14.960 Now post-finasteride syndrome is indeeda new phenomenon in the sense
01:51:19.460 that finasteride has been prescribedfor a very long period of time
01:51:23.500 for treatment of the prostate,at dosages of about five mg per day.
01:51:28.410 That’s a very high dose.
01:51:29.870 Sometimes lower, but as high as five mgper day, and for many years there was no
01:51:35.300 discussion about thispost-finasteride syndrome.
01:51:37.760 What is post-finasteride syndrome?
01:51:39.490 Post-finasteride syndrome iswhen typically it’s males.
01:51:42.800 This is where it’s been described.
01:51:44.300 We’ll take finasteride at any rangeof dosages, from 1mg to 5mg per day.
01:51:50.160 They’re either doing this for prostate ormore likely they’re doing it to offset
01:51:54.150 hair loss and increase hair growth,and then they stop taking finasteride
01:51:57.920 for whatever reason,financial or it wasn’t working for them
01:52:00.460 or the side effects were not to theirliking, and they start to experience some
01:52:05.500 very severe what can only be calledsyndrome effects,
01:52:09.110 such as very reduced libido,very reduced erectile function,
01:52:15.190 very reduced mood to the pointof depression, even suicidal depression.
01:52:19.630 This is pretty scary stuff,especially since it’s occurring at an age
01:52:23.360 when most of these things arenot typically occurring in males.
01:52:26.260 They can occur, but they’re not typical
01:52:28.290 of younger males in their20s and 30s and early 40s.
01:52:31.520 We have to ask ourselveswhat’s going on here?
01:52:33.320 After all, people have taken finasteridefor the prostate at fairly high dosages
01:52:37.200 without this post-finasteridesyndrome when they’ve stopped.
01:52:39.920 Now these young males are taking
01:52:41.520 finasteride,they’re coming off finasteride
01:52:43.140 and they’re getting this very severe, verydebilitating post-finasteride syndrome.
01:52:47.270 This has become a hot topic,
01:52:49.160 enough so that medical doctors who havebeen prescribing finasteride for a very
01:52:52.760 long time, have beenforced to address this.
01:52:54.880 I think at first they were perplexed
01:52:56.480 and thought, I don’t know, this mightbe psychosomatic, whatever that means.
01:52:59.440 As a neuroscientist who works on mind-body
01:53:01.500 connection, we know that nothingis truly psychosomatic.
01:53:04.380 Everything is of the mind and body.
01:53:06.460 But the point is that enough medicalattention has been placed on post-
01:53:10.110 finasteride syndrome and tryingto unravel exactly what that is.
01:53:13.950 Where there are now a few generalconclusions about what might be going on.
01:53:18.550 First of all, it seems that younger males
01:53:21.670 taking finasteride in particular highdosages to improve hair growth or offset
01:53:25.950 hair loss seems to beone of the key variables.
01:53:28.910 We’re not seeing this post-finasteridesyndrome as much in older males.
01:53:33.070 In fact, it seems to occur more in males
01:53:35.910 in their 20s and 30s thanmales in their 40s and older.
01:53:39.150 One thing and it may relate to the waysin which Dihydrotestosterone, we know,
01:53:43.910 has a very key role in earlyembryonic development.
01:53:47.270 It’s actually what’s responsiblefor the male genitalia.
01:53:50.040 It’s also responsible for certain things
01:53:51.910 in female development,but mainly in utero,
01:53:54.200 it’s responsible for male development anddevelopment of the penis in particular.
01:53:57.710 Then around the time of puberty,
01:53:59.870 Dihydrotestosterone acts again,in what’s called its activating effects
01:54:05.450 to further increase growthof the genitalia, increase the musculature
01:54:09.920 bone growth, et cetera, and increaselibido and a number of other things.
01:54:13.280 It’s probably also involvedin the activation of puberty.
01:54:16.040 It’s certainly not the only hormoneinvolved in the activation of male
01:54:19.440 puberty but it’s certainlyone of the key players.
01:54:21.880 Dihydrotestosterone has these known earlyroles in embryonic development
01:54:26.340 and in puberty, but what post-finasteridesyndrome seems to indicate is
01:54:30.460 that Dihydrotestosterone is likely havingfurther effects on male maturation,
01:54:35.380 in particular,maturation of the hypothalamus in areas
01:54:38.460 of the brain that continue wellinto one’s 20s and maybe even one’s 30s.
01:54:43.270 Here I just want everyone to keep in mind
01:54:45.500 that we tend to think about development aschildhood, teenage years, young adulthood,
01:54:51.950 adulthood, but reallydevelopment never stops.
01:54:54.320 Development is something that starts
01:54:55.790 at conception and birth, of course,and then extends all the way out
01:54:59.480 until the point when we die,so even if we live to be in our late 90s
01:55:02.790 or achieve 100 years of age,development is occurring that entire time,
01:55:06.720 and these different hormones such asDihydrotestosterone are having different
01:55:09.910 impact for across the lifespan andin different ways across the lifespan.
01:55:14.870 There isn’t a clear conclusion about whatpost-finasteride syndrome is really all
01:55:19.550 about, but it points to the factthat DHT is likely to be involved
01:55:22.910 in development of the brain and the brainto genital axis,
01:55:27.560 because I mentioned that because so manyof the side effects
01:55:30.280 that are associated with thispost-finasteride syndrome seem to center
01:55:33.320 on sexual side effects, although thereare also the depressive side effects.
01:55:36.560 Of course, those can be relatedto one another in either direction.
01:55:39.500 While I do understand that loss of one’s
01:55:42.270 hair, or potential loss of one’s hair canbe particularly troubling and anxiety-
01:55:46.830 provoking, even cause depressionin some cases, I am sensitive to that.
01:55:50.480 You also want to be sensitiveto the fact that some of these treatments,
01:55:53.910 such as finasteride,can carry very serious side effects even
01:55:57.190 if you come off them AKApost-finasteride syndrome.
01:56:00.770 As long as we’re talking about finasterideand this general pathway of 5α-Reductase
01:56:05.030 inhibition and thereby DHT inhibitionand on and on topics and themes
01:56:09.460 and nomenclature you are now very familiarwith, we have to talk about dutasteride.
01:56:15.570 Dutasteride is yet another moleculesimilar to finasteride,
01:56:19.590 but remember those three isoformsof the 5α-Reductase enzyme?
01:56:23.610 Well, it inhibits all three,
01:56:25.830 mainly type one and type two, but alsotype three, and it does it very potently.
01:56:30.840 As a consequence,the typical dosage of oral d utasteride,
01:56:35.730 get this, 0.5mg to 2.5mg taken orally,works 2-5 times faster than typical
01:56:44.230 finasteride at inducing hair regrowthand reduces DHT by, get this, 95%.
01:56:52.230 It’s just near flatlines DHT,and that can occur at concentrations as
01:56:57.150 low as 0.5mg, although you will seeprescriptions and people taking d
01:57:02.130 utasteride anywhere from 0.5 mgall the way to 2.5mg orally.
01:57:06.190 Now, not surprisingly,
01:57:08.000 dutasteride is associated with a lot ofside effects related to the DHT pathway.
01:57:12.270 Things like reduction in sex drive,
01:57:14.340 reduction in overall drive,it also tends to impact other hormone
01:57:19.440 pathways, so it increasesin estrogen prolactin.
01:57:21.750 That’s why gynecomastia,
01:57:23.880 growth of male breast tissue sometimesoccurs when people take dutasteride and so
01:57:27.480 you’re probably asking,why would anyone take dutasteride?
01:57:30.270 Why not just take finasterideand wait for that hair growth?
01:57:33.480 Well,
01:57:34.530 the answer is that people are often veryimpatient, and it turns out that d
01:57:38.330 utasteride works, about 2-5times faster than finasteride.
01:57:42.630 Some people don’t want to wait a full 30
01:57:45.270 weeks or 40 weeks or 50 weeks or morein order to grow their hair back,
01:57:49.000 and they’re very concerned aboutthe hair loss that’s occurring.
01:57:51.340 They will take what I hope wouldbe a very low dose of dutasteride.
01:57:56.570 I realize that there are ways
01:57:58.190 to take dutasteride that can be safer,off set some of these side effects.
01:58:02.190 But by my read of the literature,if one is going to try to mildly inhibit
01:58:07.070 the DHT pathway, things like saw palmetto,things like topical caffeine,
01:58:11.920 which has some effect on the androgenpathway, but as we talked about earlier,
01:58:15.670 tickles other pathways,things like ketoconazole,
01:58:19.070 mild reduction in androgen receptorpathways in the follicle and very direct
01:58:23.160 because it’s applieddirectly to the scalp.
01:58:24.640 Things like that are going to be the best
01:58:26.230 route for mild reductions in DHT asan attempt to maintain hair or grow hair.
01:58:31.590 Whereas if one really wants a potentstimulus for increasing hair growth,
01:58:36.030 that’s very likely going to befinasteride, and hopefully low enough
01:58:40.150 dosages of finasteride and hopefullya patient enough patient person that they
01:58:46.600 are willing to wait the duration of timerequired for that hair growth to come back
01:58:50.420 because they understand that theirantigen phase takes some time.
01:58:53.680 Now the holy grail of all this hair stuff
01:58:55.630 is in understanding that no one specifictreatment is magic, and in fact,
01:59:00.500 there are now a number of good meta-analysis comparing the various
01:59:04.200 treatments we’ve talked abouttoday alone or in combination.
01:59:06.990 We can summarize that pretty easilyby saying that combination treatments
01:59:11.270 that involve a mechanical stimulusand a chemical stimulus are always going
01:59:16.680 to be better than either one alone,and within the mechanical category,
01:59:19.950 the stimulus that seemsto work best is microneedling.
01:59:23.590 The combination of microneedlingand finasteride, can lead to some pretty
01:59:27.630 robust and impressive hair regrowth,so much so that people that were…
01:59:31.690 I would only describe them as pretty bald
01:59:34.110 or bald, can regrowsignificant amounts of hair.
01:59:37.020 I’ve never seen examples of people
01:59:38.750 who were completely bald,meaning lacking all scalp hair to grow
01:59:42.560 back a full head of hair,but the combination of microneedling
01:59:45.630 and finasteride is probablythe most effective way to go.
01:59:49.000 If you’re going to do that,there’s no reason why you couldn’t also
01:59:51.750 use ketoconazole shampoo,could also use saw palmetto.
01:59:55.560 There’s no reason to think that thesethings collide with one another,
01:59:58.230 although anytime you’re inhibiting a DHTpathway, or whether or not you’re
02:00:02.040 increasing or decreasing any hormonepathway for that matter,
02:00:04.760 you want to be careful about layeringin too many different treatments because
02:00:07.870 you don’t want your DHTlevel to go too low.
02:00:10.080 Let’s keep in mind that even if you takea very low dose of finasteride and reduce
02:00:14.070 your DHT and don’t have side effects,maybe just the mere addition of
02:00:17.550 saw palmetto, which leads to a slightreduction in DHT combined with some
02:00:22.240 caffeine ointment,would be sufficient enough to start
02:00:24.380 inducing some of the lowDHT associated side effects.
02:00:27.590 You really have to see for you,
02:00:29.360 and that’s one of the major issuesin this whole field of hair growth
02:00:32.670 and regrowth is that people are highlyindividual in their response,
02:00:36.990 and in their side effect profileto these various treatments.
02:00:40.000 There’s an enormous range there
02:00:41.230 and unfortunately, there’s no way to knowa priori before doing these treatments
02:00:45.860 what your response is goingto be in terms of side effects.
02:00:48.760 You’re simply going to have to explore,and I would hope that you would explore
02:00:51.380 starting with minimal,possible effective dosages,
02:00:54.560 and to do that in coordinationwith a medical professional so you could
02:00:57.320 really evaluate these things that thelevel of blood, and cosmetic changes.
02:01:00.950 In fact, that’s a pretty good motivator
02:01:03.040 for thinking about the differenttreatments that we talked about today.
02:01:05.670 Everything from mechanical treatments,
02:01:08.280 as simple as massage,which we’ve all heard about,
02:01:10.440 but for which there really aren’t a lotof data for supporting hair growth.
02:01:13.710 But certainly things like microneedling,which is a mechanical stimulus
02:01:17.710 for which there are pretty good datathat it can improve hair growth.
02:01:21.490 Also things like saw palmetto,a weak DHT antagonist.
02:01:25.800 Also things like ketoconazole shampoo,which again is a weak DHT antagonist
02:01:30.460 and operates through some other pathwaysas well to stimulate hair growth.
02:01:34.230 My suggestion is that anyone young, old,
02:01:36.630 male, female, who’s thinking aboutembarking on various treatments for
02:01:40.880 offsetting hair loss and stimulating hairgrowth, consider both mechanical
02:01:44.380 approaches, and the approaches that attackthe chemical pathways,
02:01:47.990 that can stimulate hair growth, and caninhibit the inhibitors of hair growth.
02:01:53.360 In fact, that’s the reason why we spend somuch time on the biology of hair growth
02:01:57.110 and what shuts down hair growth earlyon in today’s episode,
02:02:00.830 and then systematically went through eachof the various treatments that relies
02:02:05.500 on and in some cases hinges entirelyon either a mechanical stimulus or
02:02:09.950 a chemical stimulus in orderto exert its effects.
02:02:12.770 My goal today was not to overwhelm youwith a ton of biology about hair,
02:02:16.670 although we did cover a lot of biologyof hair and stem cells and hair growth.
02:02:20.610 My goal in describing all that was reallyfor you to be able to hear about various
02:02:24.750 treatments, whether or not it’s lasers orPRP or finasteride, dutasteride,
02:02:29.610 or whatever is coming next that we’resure to hear about soon online
02:02:33.340 and from the medical community,and to be able to place those into bins
02:02:36.990 related to their known or potentialmechanisms and then to be able to step
02:02:41.500 back and evaluate, which, if any, of thosetreatments might be right for you.
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02:04:29.840 Thank you for joining mefor today’s discussion.
02:04:31.760 All about the biology of hair and hair
02:04:33.710 growth, how to hold on to the hair youhave and to stimulate new hair growth.
02:04:38.590 Last but certainly not least,thank you for your interest in science.
02:04:42.880 [MUSIC PLAYING]