/r/HaircareScience
This subreddit aims to provide resources for achieving better hair quality through scientific research in trichology, physiology, chemistry, and biology
This subreddit is for discussion and dissemination of the science behind haircare products and processes. We aim to provide information and resources to achieve better hair quality through scientific research in trichology, physiology, chemistry, and biology.
see front page without Advice Request posts
Subreddit Rules
Source your facts - If you're making a statement of fact, you must provide a scientific source. If the information comes from somewhere non-scientific (your experience, a blog), you must make that clear and not frame the statement as fact. Do not tell others to look things up for themselves - the burden of proof is on the person who first posts something. Read more about what qualifies as a source here
We are not your doctor - Do not ask for a diagnosis or attempt to give one to anyone else. If you want to ask about a particular condition it must be in an impersonal way and it must not ask for how to diagnose.
Advice requests must be specific - Requests for personal haircare advice must have a specific question in the post title. Vague requests (“what’s wrong with my hair?" "Give me product recommendations”) will be removed. Please post general requests for help/recommendations in the stickied Haircare Advice megathread, or rewrite this post to have a more specific question. Read more about what makes a post specific vs. vague here
No repetitive posts - In order to keep the subreddit uncluttered, questions that are frequently posted will be removed. Before posting, use the search bar first to see if your question has already been discussed.
This is a science subreddit - This is not the place to ask for styling preferences - try other hairstyling subreddits for that. Pseudoscience, chemophobia, or other anti-science rhetoric will be removed and repeat offenders banned.
No advertising - Advertising a product without any scientific discussion is prohibited. If you are affiliated with any product you must disclose your relationship. You may discuss your products as long as you have disclosed your relationship and have been flaired as a product representative. Product recommendations are allowed as long as it is not repetitive and you do not ask to take the conversations to DM or post affiliate links. We have a zero tolerance policy for advertising or promoting MLMs.
Be respectful - Scientific arguments may sometimes occur, but always treat other users with respect. No harassment/racism/sexism/etc. will be tolerated. If you are combative or rude when others ask you to provide sources, you may be banned. This rule also applies to your communication with the mod team.
No asking for advice on balding or hair loss of any kind. - If you have any questions about hair loss, balding or thinning please consult a medical professional. Other subreddits you might be interested in include r/tressless and r/askdocs.
This is not a product review sub. - Product ingredient lists don't really tell us much about the product; formulation matters. If you're looking for product reviews, try another sub, or google it. Same applies to posts asking for dupes of a specific product. Posts asking for help checking a product ingredient list for "harsh" or "harmful" ingredients will be removed as it promotes chemophobia.
This is not a hair coloring or styling sub. - For hair color advice, try r/hairdye or r/fancyfollicles. For hair styling advice, start at r/hair.
This is not a DYI sub. - There is a perfectly good DIY subreddit, r/DIYbeauty. Post homegrown product questions and other DYI fair product questions to that sub.
Asking Advice?
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If you make several well-cited comments, you can get special flair to distinguish you as a knowledgable hair person. Gives you extra credibility!
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If your posting history indicates that you are a company or product representative, you need to be assigned brand representative flair in order to post about your products on this subreddit.
Resources
Alphabetical List of All HCS Guides
More Information
International Journal of Trichology Archive
North American Hair Research Society
Chemical and Physical Behavior of Human Hair by Clarence R. Robbins
Hair and Haircare, ed. Dale H. Johnson
Cosmetics & Toiletries Magazine
Journal of Cosmetic Science Archive
Brightest Bulb in the Box Blog
Related Subreddits
/r/HaircareScience
I accidentally straightened a piece of my hair while it was still a bit damp. this was about a month ago and my hair still has a lingering burnt smell. I lather my hair with conditioner in the shower and use smelly products afterwards (leave in conditioner, creams, oils) and the burn smell penetrates all of that within hours. it’s not a pleasant smell and it’s starting to drive me crazy. what can I do?
Hello, I have pretty dry hair and live in the desert lol. I have been using the hair mask with conditioner (redkin acidic bonding). Should I skip the conditioner?
Does it actually work? Has anyone heard of it? Is it just the new product being pushed this month? Spill the tea
I mostly cut my own hair, i find it enjoyable and i feel like only i know what i like, but i never bought i pair of GOOD scissors.
I use the kitchen or school ones and i never had a problem, until recently, my hair has gotten long enough for me to see it without a mirror (over my chest) and i noticed a lot of split ends, so i began cutting then on the bus or when i have time to kill, but i feel like no matter how many i cut, i see more and more split ends.
Could i solve it with good scissors or is it be something else in my routine? How can i know if the scissors are good or not? What brands do you know?
Sorry if my English is bad, it's not my first lenguaje
I've never understood how oiling your hair can actually help it. Realistically, regardless of how long you leave it in your hair, you're just washing it out after with shampoo right? So how does it actually DO anything?
I’ve been perming my hair for about 4 years now about every 7 months and I’m at the point where I want to go back to my straight hair. It’s been almost a year without perming it and it’s still curly. I stopped using curling shampoo and curling cream but it’s still curly. What can I do to help make my hair straight again.
I understand that washing hair with shampoo is bad for your hair but is it also bad to wet your hair daily ?
First off wanted to say nizoral had immediate benefits with the oiliness,itchiness and the ratchet smell.
My doctor said this would stay with me the rest of my life so should I use the shampoo everyday for the rest of my life? And does it damage your hair with constant use because of all the chemicals?
Right so I'm was having a discussion with someone and they said "you always have to use shampoo for your hair" and I'm pretty sure that you could live your whole life without using shampoo for your hair, but then couldn't find and research papers proving what I've said is correct. Am I just dumb or just a bad researcher ?
i live in asheville and due to hurricane helene our water supply was heavily contaminated and they are pumping chlorine in it to clean it. it has been stated that it’s safe to shower in. my roomate bought a filtered shower head off amazon just to lighten the contamination load but obviously it’s just kind of a bandaid. my hair has dryed out significantly and is breaking a lot. are there any treatments/ steps i can do to keep it healthy?
Shaving head for healthy hairs! Does shaving your head make your hair grow thicker?
So I’ve always had a battle with my hair porosity, but I came to a confusing realization after doing my hair wash today.
I always used to tie my hair up in a quick bun after a wash so I could take a shower afterwards and my hair would always be wet or damp still after a few hours so I had the impression that my hair is just always damp or wet after washing. I then lately would not tie up my hair and just leaving it down and I had been noticing my hair would dry like incredibly fast but I didn’t make the connection til now.
Today after washing my hair I put it in a bun and even like three hours later, my hair is still damp in a bun and I thought that was crazy because I got used to my hair drying incredibly fast like 10-15 minutes fast or even less than that.
Is there a reason to this tying up your hair right after washing it leaves it wet, but if I let it down just air drying after a wash the entire time, it dries faster? Is that the underlying factor in why my hair is still damp now but wasn’t previously?
Not sure I just am curious because I noticed how quickly my hair dries compared to when I was younger where I did tie my hair in a bun after washing my hair. And to be honest, my hair drying out fast kind of annoys me especially when I want to style it. (I have 3B-3C hair) anyway thank you!
The absolute best mask I have ever used on my dry, frizzy, hagrid hair. It’s been discontinued and usually comes out at Christmas holiday season however has not been released past two years. Do we know anything similar ? What’s your most trustworthy hair mask for dry coarse and damaged hair? Or is anyone knows a dupe for Apple honey brieogo ?
Does anyone have any insight into why my hair (fine, lots of it, 2A) will not hold a curl/wave when I use a hot tool — curling iron, wand, straightener, Dyson, etc., but when I used an overnight hair curling rod, my hair actually held the curls? If it makes a difference, I live in south Florida (high humidity), my hair is color treated/bleach (but not for at least a few months), and I have a somewhat fresh Brazilian blowout. I have used mousse, texture spray, hair spray, and any other recommendation I’ve seen for when hair won’t hold a curl.
Hello! I need some help with my hair... I was living in AZ a few years and had long glossy hair. It was so pretty! Really thick and had some nice waves to it whereas it used to be straight and dull. I moved back to NH this summer and my hair is just awful now even months later. I'm pretty well settled and not super stressed. It was humid and hot when I arrived (as opposed to the extreme dryness of AZ) and now it's not humid and quite cold. I don't know what's messing with my hair but it's so lank and it gets so greasy so fast especially if I go to bed with it wet. I did also go off hormonal birth control when I moved but it's been several months. My fiancé insists our water is less hard than AZ but I'm not quite sure he's correct. Does anyone have a clue what might be the biggest contributor here? It is so so frustrating to just look in the mirror everyday. Thanks in advance!
I have dark black hair and accidentally bought the white dry shampoo. Can I put a dark finishing powder in it so it doesn't show as much in my hair? Will that change anything at all? I don't want it to go to to waste D:
Hair conditioner doesn't do anything for men. The primary target for hair conditioner is women which sounds sexist but if you look at commercial there has never been a male using hair conditioner. Shampoo yes but hair conditioner no unless it's a two in one bottle. Now I know it says it good for hair health but it's not really true. 300 years ago hair conditioner didn't exist yet people had hair that was more moldable than it is now.
I have relatively straight asian hair but ever since i was in highschool or so? I would have periods where random pieces of obviously thicker, coarse/kinky hair strands would pop up here and there.
I would search through my hair to find them and pluck them out because it feels sooooo good.
Why do these hairs come up??
And for some reason, at least for me, I get them more during periods of stress?
Sometimes I can go 6-7months without any and then they'll be back again.
At home, my hair is fairly soft. Humidity is lower than Hawaii. From what I can find, hawaii has soft water. Im from San Francisco which also has softwater. But my hair feels crunchy the day after I wash it. Is it the salty air? Im asian with slightly wavy hair. Not dyed or bleached.
Hi! I am unable to understand why my hair turns greasy and limp the day after washing it, when the weather is cooler and less humid. Consequently, it stays perfect when I am in a place that has higher temperature and high humidity. Is there anything I can do to counter this problem? Thanks for any tip and/or product recommendation.
um a lot of context is needed but basically i had gotten my haur cut some time in 2022 and on october 10th i got it cut for the first tike since tgen, wanna say i chopped off a good 6-7 inches and my hair was like so dead and split and i had breakage. i started to notice a few split ends like a week ago and now there r defff way more…. just wanna know if it’s normal for my hair to split fast sicne it was so damaged before or did i already make my hair bad again. i tried looking it uo and thee google ai thing said that ends can split fast if your hair was super damaged before a cut but i also dont trust the google ai…
So I’ve heard almost everywhere that massaging your scalp helps with hair growth by improving blood circulation in the scalp. However, when I do it, my scalp always itches after. I thought it was something I was doing wrong at first, so I looked up countless of tutorials and researched all throughout the internet “how to properly massage your scalp” and I see many different methods and motions which overall just confuses me. Does massaging your scalp REALLY improve hair growth? How do you properly do it? Is it supposed to itch or something?
I have very coarse thick hair and so I can see the shape of each strand. When I see diagrams of hair strands they’re round. But mine are flat. From one angle they’re thick and then from the other they’re thin like a ribbon (thinner than that of course but shape wise). Not all of the hairs are thick enough to tell but if I manage to catch one that is I’ll post a picture.
I'm in San Diego, CA this weekend along the coast and my hair has been a pain the entire time (usuaply the case out here). It won't hold any volume for more than an hour so before it starts flattening out from every molecule of water in the air.
As an FYI I have thin hair not very dense as far as coverage either - usually blow dryed, straightened a bit with an iron and styled with a side part. I use American Crew high hold high shine pomade and Sebastian Reshaper hair spray.
Suffice to say this drives me nuts. Got any dips?
I see a lot of black owned oil companies saying to apply the oil everyday, even leave it on all night. Where as maybe a white person or middle eastern/asian, they would say oil 2-3x a week and leave it on for 1-2 hours. Personally if i left oil on my hair all night i d get an infection and very itchy scalp.. So whats the reasoning
i was being irresponsible in organic lab the other day and i think i got some stuff im my hair. its weirdly greasy/stickey? in kind of a large spot on the top of my head. im pretty sure i ran my hand through it and tied it up again during lab, and i wasnt wearing gloves that day.
im pretty sure the stuff i was handeling was ethanol, petroleum ether, acetone and an unknown basic substance we are identifying (i believe is p-toluidine).
i tried washing my hair and the spot wont come out! i dont know for sure if it happened during lab but i have no idea when this could’ve happened! if it was from lab is there anything i could do to fix it?
I’m sorry if this comes across as stupid - I’m genuinely curious and have never been able to understand the science of this.
If losing 100-150 hairs per day is normal, then why does hair continue to look full? Surely we’re not sprouting 100-150 hairs a day, so how does it balance out?
I’m aware that each hair is in its own cycle of growth and shedding, but regardless, how does it balance?
Thank you!
So I’m learning that hair actually needs less or very little water in it with products in it so it doesn’t dry out. My question is how do we apply products while also eliminating as much water as possible? Don’t products need water to absorb into hair especially like my low porosity hair?
I have straight but wavey low porosity hair. I used to shampoo using drugstore shampoo daily. I had to due to hard water and the state of my hair. I've started using a natural shampoo without sulphates or silicones. The conditioner I use is the same and I use all 7 days in between.
I don't like how when I wash my hair with normal shampoo or even this natural one, all the volume that's built up goes away from my hair. When I co-wash my hair it makes it super soft, super clean, and beautiful. It feels like it's been shampooed. I want to stop using shampoo altogether and just use this conditioner.
Can I? It's a clarifying conditioner so it seems to clean my hair without stripping it at all like the shampoo does. My hair has never been in such good condition. Thoughts?