Articles, Blog

What Actually Causes Dandruff?

August 14, 2019

Hey! This episode was sponsored by Head & Shoulders. A hundred and twenty-five million years ago in what is now China, dinosaurs walked the earth. and a few species of small feathered dinosaurs climbed trees This is Sinornithosaurus Although they couldn’t truly fly, they could glide, which helped them evade predators and catch prey What makes these dinosaurs unique is how well-preserved their fossils were. Normally when you find a dinosaur it’s just a pile of bones and that’s all there is. In between the feathers and the parts of the feather we saw little bits of skin And you can tell that they are skin – they’re not just random bits of rock or broken up bone or something because they have a particular kind of cells within the structure which are just like the skin cells that we find in humans today Well, my first thought when I saw these was this is dinosaur dandruff and I was already planning to write the paper with the headline of we have discovered dinosaur dandruff, I thought great. So these dinosaurs may have had the first known case of dandruff. But it certainly wasn’t the last Our skin cells are constantly replenishing themselves in fact every second 500 new skin cells are created and as they move up through the outer layer of your skin, the epidermis They flatten out and harden until they fall off one by one In fact over your lifetime you will shed about a hundred pounds of dead skin But we don’t really notice this because skin falls off in such tiny microscopic pieces except for some people from some parts of the body skin comes off in larger flakes typically from the skin under the hair the scalp and this is what’s known as dandruff Now around half of everyone on earth suffers from it. So there are actually a lot of scientists who study this condition. and I’m flying to Cincinnati to Head & Shoulders headquarters to visit their lab Okay. Do you need a break or something? No, it’s funny like ’cause I’m not really sure what I’m getting myself into right No. No. I am going to have my head swabbed Mm-hmm. You are What what is that all about? I mean, this is something you do to people all the time? Oh, yeah. Every day. –You’re gonna cotton swab my scalp. –Yes And we’re looking for what? So we are gonna be looking for the malassezia that is on your scalp. Okay, so what do I need to do? So I need you to have a seat here. Let’s see and I just put my head in here? Yeah, put your head face forward. Okay. What I’m gonna do is I’m gonna part your hair. So now I’m gonna take my swab I’m basically gonna grab off your scalp. Mm-hmm So then what I do is I take this These are sticky plates here that I can plate the malassezia on and what I can do is I can add a stain throw this under the microscope and this is the individual cells of malassezia here. Malassezia globosa is a fungus that lives on your scalp it thrives in the warm moist environment under your hair and it is thought to be one of the causes of dandruff. So, how did my swab come back? Well, I have malassezia living on my head. This is actually what the fungus looks like. This is a lawn of the Malassezia globosa fungi. You say a lawn. It’s a lawn. So basically you can see those little dots they’re all individual colonies and when they grow really close together like that, that’s a lawn, Kind of like a bunch of grass Now that I’m close to and actually smell it it smells like bread Yeah, well, you know, it’s a yeast You know it’s a free, living fungus just like the Saccharomyces that are used to make bread and make beer with So, could you make bread with this? Uh.. No. I wouldn’t want to make bread with the yeast off of your scalp. Not right now. — Have you been tested? — I’ve been tested. Yes. — And what did it come out to? I have a decent amount. So… But we all do. So… It’s on everyone’s head. It’s on everyone’s head as long as you have hair. –Right But if everyone has Malassezia, why do only half of us get dandruff? Well Malassezia lives on the oils called sebum secreted by your skin The fungi release enzymes called lipases that break down fat molecules Oh, so this is one of the lipases that Malassezia produces So this is something that Malassezia uses to get food But unfortunately as a byproduct of that it also attacks your scalp because it produces free fatty acids that irritate the scalp for some of us those molecules are perceived as invaders if you will and all the defensive forces that we have will get turned on to repel essentially these invading molecules and those defensive forces end up causing this collateral damage that we interpret as an unhealthy scalp and dandruff One of the scalps defenses is to speed up the turnover of skin cells So instead of taking a month for skin cells to mature and reach the surface they take as little as seven days When you know they get to the surface the adhesive function from one cell to the other hasn’t been lost And so they shed as these clumps of skin cells three or four hundred together, which we see as a dandruff flake the dandruff flakes are just an indicator of a fundamentally unhealthy scalp underlying it by any measure you can dream of making Dandruff skin samples show elevated levels of inflammatory cytokines Histamines which cause itching, and blood proteins on the surface of the scalp Indicating that the skin is not acting as a good barrier between your insides and the outside world But it goes even further than that down to the level of gene expression Scientists took swabs from healthy scalps and dandruff scalps and then they extracted the RNA Effectively markers of which genes are being expressed and how strongly and then they compared the two groups and they found that there were nearly 4000 genes which were systematically either up-regulated or down-regulated in the dandruff scalps compared to the healthy scalps for example immune and inflammatory response genes were up-regulated, things like lipid metabolism were down regulated and it all kind of makes sense But now that you know that there’s a difference at the level of gene expression, How do you actually treat dandruff? So this is the the lawn of Malassezia. This is the Malassezia with a spot of the Head & Shoulders active put on it The Malassezia just doesn’t grow where that Head & Shoulders active actually is These active ingredients can be zinc pyrithione, selenium sulfide, or piroctone olamine. They are controlling the metabolism of those Malassezia cells that are leading to irritating substances so the idea is to suppress their bio activity to some extent so that we’re reducing the level of irritating substances on our scalp that trigger the irritation and hyperproliferation and buried destruction that we talked about now that we understand like these clusters in these genes signatures of dandruff is Can we reverse these gene signatures if we treat with Head & Shoulders? So this is the group of dandruff at baseline and these genes are all down-regulated and then these genes are up-regulated You can see if you treat with just a cosmetic shampoo that you really don’t make a difference in those genes But if you treat with Head & Shoulders after three weeks This signature looks just like somebody who doesn’t have dandruff. And so you’re looking at 3,700 genes have all clustered all on here, And you’re seeing them flip around. They’re going from an unhealthy signature to a healthy signature So Head & Shoulders reduces the Malassezia irritants on the scalp, changing your scalp‘s response, and ultimately reducing skin flakes So unlike dinosaurs, we don’t have to live with dandruff But in their case the presence of skin flakes reveals something important about their biology They had evolved warm-bloodedness and hence feathers as a way to keep warm But once they had feathers skin could no longer be shed in one piece like a snake but instead in tiny pieces So in fact, although it’s an amusing discovery it actually had quite an important or profound point because it tells us that dinosaurs while commonly called reptiles are on the side of the birds and the mammals in terms of physiology. They were definitely warm-blooded Hey, I hope you learned something from watching this video I certainly learned a lot making it. and if you want to find out more about Head & Shoulders research or about how to get rid of dandruff I will put a link to their website down in the description so I want to say a big thanks to Head & Shoulders for supporting this episode of Veritasium and I want to thank you for washing. Or, watching


  • Reply Canis Poetam July 4, 2019 at 12:41 am

    fascinating video. who ever would have guessed that dandruff would reveal dinosaurs as warm blooded beasts.

    On the flip side, and a much more personal level, this touches on a particular gripe of mine. I use head and shoulders. I have a large and new bottle of the shampoo in my shower this moment. It's one of them new fangled plastic pump bottles. Two in One, 32 oz Question Everything But Yourself #Headstrong pump bottles.

    The pump doesn't work.

    I presume the reason why is because a break off snap ring was designed into the head of the pump, and it won't break off. I've tried to pry it off, and only succeeded in slicing my thumb.

    So I've purchased an economy sized bottle of shampoo with a new feature that doesn't work, and in the end results in wasted product and even minor injury.

    Tsk Tsk.


  • Reply Venkatesh Babu Ponnuchamy July 4, 2019 at 11:58 am

    Dandruff means death of soul and brain cells.

  • Reply Gaurav Tiwari July 4, 2019 at 4:37 pm

    If H&S really wanna cure dandruff then don't you think there would be no use of there product why would they'll do that… Its Against there monopoly !!!

  • Reply IE B July 4, 2019 at 4:59 pm

    My solution to dandruff was going bald. Ever since I started shaving my head, I haven't had any issues. Before I had to sometimes even resort to antifungal shampoo

  • Reply seattlegrrlie July 4, 2019 at 9:11 pm

    My itchy, blistered, oily scalp is definitely unhealthy.

  • Reply Daniel July 5, 2019 at 12:54 am


  • Reply Savira Ananda Pritania July 6, 2019 at 8:13 am

    Who else screamed a little when he was sniffing Malassezia out of the petri dish

  • Reply Ifada Academy Tv July 7, 2019 at 3:55 pm

    dandruff isn’t something that I get often, but just recently I got it really badly, and I wanted to tell you guys exactly how I managed to get rid of it super quickly. Dandruff, aka a flaky scalp, can feel a bit embarrassing as it’s so hard to hide, especially if you have dark hair like mine, it’s really obvious!

    The thing is, dandruff is super common, and there are a ton of things that can cause it; from too much stress or new hair products to not washing your hair enough or the overgrowth of a yeast-like fungus. Some people are more prone to it than others, but most people will experience it at some point in their life.

    in this article will find some of the things I’ve used to get rid of dandruff, which have always worked really well for me.

    have a nice day

  • Reply Eddie Schirmer July 8, 2019 at 1:39 am

    i absolutely LOVE using "Head & Shoulders" shampoo… it really does work… I've had dandruff for my whole life, but its very well under control thanks to using it… regularly

  • Reply Rebecca Aira July 8, 2019 at 7:34 am

    the thumbnail for this is actually very cute

  • Reply Random Tube July 8, 2019 at 12:36 pm

    🤦‍♂️I wish it was that simple. Some people have very sensitive scalps resulting in more harm than good. Ive tried almost every head and shoulders with little to no improvement. They all burn and irritate my scalp bad. I even tried other brands and all kinds of home remedies all with little to no luck. Probably just going to have to go permanently bald 😭

  • Reply Caleb Stiles July 8, 2019 at 7:30 pm

    Feeling itchy yet?

  • Reply PhantomWolf37 July 8, 2019 at 11:48 pm

    ive been playing too much ark and then come to this

  • Reply Chris Sherer July 9, 2019 at 1:26 am

    my head itches now

  • Reply victor garcia July 9, 2019 at 6:14 am

    Learned something

  • Reply Change Is Coming July 9, 2019 at 7:41 am

    You’re a smart guy, but you actually think that skin has been around for 100 million years???

  • Reply Adam Perkins July 9, 2019 at 8:23 am

    So bald people have no dandruff?

  • Reply I LOVE YOU LORD July 9, 2019 at 3:17 pm

    Starts at 1:20

  • Reply I LOVE YOU LORD July 9, 2019 at 3:24 pm

    Moral: Use head and shoulders

  • Reply BlargieArg July 9, 2019 at 4:25 pm

    I'm a skin flake

  • Reply GigiSan July 10, 2019 at 8:44 pm

    So basically H&S shampoo alters DNA. Did I hear it right?

  • Reply Earth July 11, 2019 at 12:31 am

    Joked on you, after this vid I googled “how to make bread”

  • Reply Steve Chapo July 11, 2019 at 8:29 am

    I loved the British guy talking about dinosaurs. He would make a great Q for James Bond.

  • Reply Hrishikesh Kale July 11, 2019 at 3:04 pm

    Is that head and shoulders shampoo

  • Reply dan heilman July 11, 2019 at 4:12 pm

    I have used head and shoulders my whole life, i've had dandruff my whole life. I started using my wifes argan oil shampoo with no parabens and my dandruff improved.

  • Reply Xiangyun SHI July 11, 2019 at 4:24 pm

    Maybe later? lol

  • Reply Jeff Sadowski July 11, 2019 at 4:45 pm

    Kind of explains why I had more dandruff problems before I went bald.

  • Reply Da Do July 12, 2019 at 1:26 am

    Amazing video

  • Reply Razor Ransom July 12, 2019 at 8:42 am

    So technically it's all an allergy, huh. We'll add another one to my family's absurd/super rare but sadly true list of them. Mom's side is to blame for all!😭

  • Reply . July 12, 2019 at 8:27 pm

    Head and shoulders burns your nipples, testies and arse. Bad for your head too.

  • Reply Aurongroove July 13, 2019 at 4:10 am

    First three seconds of the video.

  • Reply Kevin Martinez July 13, 2019 at 3:35 pm

    Nahhh i use HS and that thing doesnt work for anyone!!!

  • Reply itsLean ★ July 14, 2019 at 1:47 am

    HEad n shoulders is crap.

  • Reply atk2597 July 14, 2019 at 8:50 am

    What actually causes dandruff??

    -Not using head & shoulders.

  • Reply sumaiya noor July 15, 2019 at 5:32 am

    If Head & Shoulder can make Para-ban free, Sulphate free, Sodium Laureate free shampoo, may be hair and scalp health conscious individuals like myself will be their customers. But not with current formula with so many harmful chemicals even if it helps in removing dandruff.

  • Reply Jonas Kircher July 15, 2019 at 9:02 am

    Maybe if they made ads like this in TV I wouldn't mind them so much. I also would maybe trust some cosmetic products more. However I doubt that this fungi is the only cause for dandruff, so it would probably still be best to go to a dermatologist and let them figure out what is causing the dandruff.

  • Reply Saadi July 16, 2019 at 5:49 am

    I used to have a lot of dandruff in my early teen years. Now im 19 and its almost gone! i dont know why or how.

  • Reply Harry July 16, 2019 at 10:18 am

    Head and shoulders?

  • Reply Harry July 16, 2019 at 10:24 am

    Head and shoulders effect my genes? I'm switching shampoo

  • Reply Omer Feldman Yofiël July 16, 2019 at 9:05 pm

    Unfortunately, he didn't address the real mystery: why Head & Shoulders shampoo contains only enough fungicide to control, but not eliminate, the fungal infection. In other words, why don't they cure dandruff, rather than just committing you to continual use of their product? For my part, I'd rather find a true cure for the disease, and not just a lifetime subscription to symptom suppression.

  • Reply Genius Dog Poocho July 16, 2019 at 11:13 pm

    I have the best hair in the world I don't use any of those products I release on YouTube eventually something amazing

  • Reply hanji July 17, 2019 at 9:36 am

    Classic ad!!

  • Reply Aditya Verma July 17, 2019 at 3:59 pm

    You make me smarter everyday..

  • Reply beyondfubar July 17, 2019 at 6:38 pm

    Ok I'll click on this dandruff video


    ::Visible confusion::

  • Reply thedanyes July 18, 2019 at 4:42 am

    Isn't it irresponsible to grow these fungi in massive colonies and then open their containers without a fume hood?

  • Reply RepublicanMug July 19, 2019 at 9:02 am

    I use anti-bacterial shampoo from the drug store time to time. It keeps skin from irritating and producing nasty clear liquid that would turn into dandruff.

  • Reply Chris July 19, 2019 at 11:24 am

    A video about dandruff starts with a dude showering and CGI chinese dinosaurs.

    This is what makes the internet great

  • Reply joseph jackson July 19, 2019 at 11:36 am

    I never had dandruff until my brother put his dandruff on me. Since then, I've had bad dandruff. MY BROTHER GAVE ME DANDRUFF

  • Reply 28Cyberwar July 19, 2019 at 5:30 pm

    When i do use other shampoo then Head and shoulders i will get so many dandruff

  • Reply Uno más del Patriarcado July 19, 2019 at 7:03 pm

    I do not buy P&G since the "toxic maculinity" propaganda…

  • Reply sarikatimmi July 20, 2019 at 5:40 am

    so also iust a big ad then

  • Reply Sanj F July 20, 2019 at 9:49 am

    It’s a harmless commensal and it probably outcompetes the bad bugs. Leave it alone.

  • Reply Revenge July 20, 2019 at 10:30 am


  • Reply Lollerkid July 20, 2019 at 4:19 pm

    Its 2018 and scientist use windows vista. Fascinating…

  • Reply SomeRandomGuy July 21, 2019 at 3:51 am

    I got dandruff genetically and I can’t get rid of it. It’s really annoying, painful and just really really itchy in my case. I can’t even wear headphones without feeling sharp pains on my head

  • Reply Leroy Zwane July 21, 2019 at 1:08 pm

    WoW M gonna be using head & shoulders

  • Reply SRunic July 21, 2019 at 5:29 pm

    This is what we're going to fight in area 51 bois 0:16

  • Reply WisdomTooth July 22, 2019 at 1:23 pm

    Ultimately stress, physical, mental, emotional stress = dandruff. External applications only work temporarily. If you do not heal the root cause/internally it will always come back. Its not worth putting toxic chemicals in your head every day for the rest of your life.

  • Reply Blah blah Blah blah blah blah July 24, 2019 at 8:54 am

    That thumbnail was a perfect mix of cringe and horror

  • Reply John Red July 24, 2019 at 4:00 pm

    I have never had a dandruff, but when i was a child i used my dad's head'n'shoulders' once and… The very next day i have dandruff… WTF?

  • Reply DumbBums c July 25, 2019 at 4:36 am

    I blame my not smart on dandruff!! How dare my head skin not protect my brain!!

  • Reply KenDBerryMD July 25, 2019 at 5:37 pm

    Interesting! So if our diet consisted of good healthy fats, very low carb intake, and our immune system wasn’t already triggered, dandruff would just go away

  • Reply TheDemon 7Seas! July 25, 2019 at 6:15 pm

    Too much biology for a 8th grader computer student like me. 😂😂

  • Reply Harsya Syabil Budiman July 25, 2019 at 8:09 pm

    I alr use head and shoulders for month and i still have dandruff.

  • Reply BigDaddy Strokes July 26, 2019 at 10:58 am

    T-Gel gang

  • Reply critical panda AHNAF July 26, 2019 at 2:55 pm

    HEY thought i hated ads

  • Reply Osmone Everony July 27, 2019 at 11:27 am

    Ugh those armpit hairs can't be unseen.

  • Reply Josip Tumapa July 27, 2019 at 5:06 pm

    I have too much of them then…. thanks again to Philippine humidity. Lol

    I’m a dandruff queen damn

  • Reply bigyabbie July 28, 2019 at 9:27 am

    sorry to see such a usually reliable presenter confuse advertising and information
    very american 🙁
    Especially given you could do the same thing with many other ways if dealing with yeast such as simply changing acidity…

  • Reply IDRES Keyboardwarrior July 28, 2019 at 7:17 pm

    Try putting aloe Vera on your head if you have dandruff. It really works I tried it.

  • Reply XxXRobloxPro123LtuXxX Pro Minecraft Videos Everyday July 28, 2019 at 7:42 pm

    head and shoulders made my dandruff worse, i cut my head bald and switched to garnier fructis shampoo. since then my hair grew about 25-30cm long, no dandruff since

  • Reply Seerkamban Elangovadikal July 29, 2019 at 6:14 pm

    A nine minute ad for Head and Shoulders.

    Well, at least it's educational. You're lucky pretty Derek.

  • Reply wheeler 22 July 30, 2019 at 3:17 am

    What do you think about making a video about how a balloon or helium balloon looses its air and helium over a period of time?

  • Reply Ameya S July 30, 2019 at 10:14 am

    T-Rex wants to borrow your shampoo

  • Reply Soumyakanti Chakraborty July 30, 2019 at 11:56 am


  • Reply Shawn Lewis July 30, 2019 at 3:44 pm

    What a way to sell shampoo.

  • Reply Sachin Pal July 31, 2019 at 8:23 am

    When I started using heads & shoulders good thing was I did not get dandruf but my hair started to fall.

  • Reply Peter Marquardt July 31, 2019 at 9:26 pm

    I'm sorry, are you really spreading their narrative that skin flakes are "unhealthy" without batting an eye and at least questioning their wording? I thought better of you.

  • Reply Kyru Cabading August 1, 2019 at 7:38 am

    Thank you! I always just thought they didn’t really care whether it was effective or not, I’ll try head and shoulders again

  • Reply Green blue August 1, 2019 at 9:12 am

    Selsun blue

  • Reply Green blue August 1, 2019 at 9:13 am

    Head n shoulders will make you get bald 👨‍🦲

  • Reply tigertank909 August 2, 2019 at 4:44 am

    and that skin that comes off you the body turns into dust 1:47

  • Reply Sharan Aujla August 2, 2019 at 3:49 pm

    Why don't we kill all the Malassazia?

  • Reply April August 3, 2019 at 12:44 pm

    Anyone else grossed out by this?

  • Reply Ed Lilli August 3, 2019 at 4:55 pm

    For anybody who low key has a crush on veritassium (me) the beginning of this video was a win

  • Reply Annie Favreau August 4, 2019 at 8:15 pm

    Great findings about dinosaurs skin! Finally I know what is the deal about this head&shoulders!

  • Reply Tyler D August 5, 2019 at 4:19 pm

    head & shoulders causes cancer

  • Reply Humble_ lion- скромный Лев August 5, 2019 at 6:04 pm

    that's some intense research into dandruff

  • Reply Sam Keller August 7, 2019 at 4:01 pm

    You should do a video on minoxidil.

  • Reply Guru August 7, 2019 at 11:49 pm

    He asked if you COULD make bread with the hear yeast, not if you SHOULD. I still want my answer.

  • Reply Perfect World of Karma August 8, 2019 at 6:57 pm

    I can only speak for myself, but if you drink less soda, eat less sugar, the dandruff will decrease. Probably dissappear if you manage to stop drinking soda completely, and keep sugar at minimum.

  • Reply Palmtreegal3 August 9, 2019 at 4:39 am

    Tea tree oil is a nice natural solution to dandruff. Just put a few drops in your shampoo

  • Reply hunter severson August 10, 2019 at 12:25 am

    Well I didnt know that that was gonna be as interesting as it was

  • Reply Shrif Adel August 11, 2019 at 10:59 pm

    Anyone here don't want to touch his hair too 😂

  • Reply dadigitechman August 12, 2019 at 5:34 am

    Subway bread

  • Reply walshamite August 12, 2019 at 2:01 pm

    It might be of interest that this yeast (Malassezia globosa) is also involved in seborrhoeic eczema (a.k.a. seborrhoeic dermatitis), affecting the face, sides of the nose, forehead, behind the ears, inside the ear canals, and other areas. In my experience as a user, anti-dandruff shampoo works great as a treatment for those areas too. The redness and flaking have the same cause, (yeast degrades skin fat [sebum], fatty acids produced cause an inflammatory response), and the yeast can be supressed in the same way.

    In my own case, I have found it also effective for the related fungal infections of tinea pedis (athletes foot), tinea cruris (jock itch/ringworm) and the skin pigmenting tinea versicolor (Pytiriasis). Same method applies. Wet area, apply shampoo, foam in, leave on for a minute or two, rinse off and dry. I apply such shampoo on a sponge in the shower, to my scalp and anywhere else my experience indicates it might be of benefit. People who have fungal problems on one area of the body tend to be prone to fungal problems on other areas. NOTE: I merely relate this as personal testimony of how it works for me … I am not giving medical advice.

    You'll find these antifungals are pretty generic; that is, zinc pyrithione is also used to stop fungal rot in fencing timber! Other antifungals, like the azole group, e.g. ketoconazole, also kill or inhibit fungi and will have the same effect. To lean more,wiki search on fungi, zinc pyrithione, piroctone olamine, selenium sulphide/sulfide, ketoconazole, Malasezzia.

    Fungi are a huge group of 144,000 organisms from yeasts, rusts, smuts, mildews and molds, to toadstools and mushrooms. Mostly, they serve a very valuable role in nature, helping breakdown dead plants and animals to return their goodness to the soil. Unfortunately, some are pathogens.

  • Reply Humboles August 12, 2019 at 4:08 pm

    For very persistent cases of dandruff, try new Head and Ankles…

  • Reply Danae Lum August 13, 2019 at 8:07 am

    Okay I'm gonna buy some Head and Shoulders tomorrow

  • Reply Deepak Dev August 13, 2019 at 3:59 pm

    Hair transplant ad after the video as if 9 minutes of head and shoulders was not enough!!

  • Reply gage taylor August 14, 2019 at 3:48 am

    Keep spreading knowledge! 👍

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