Scientist explains: What everyone gets wrong about sulfates in shampoo

Do sulfates really strip hair, or clean better? I'm doing a deep dive into the science of how shampoo actually works, and why hair science is so confusing.

In this video:
0:00 Hair science is a mess
1:07 Diversity of hair
2:27 Straight vs curly detangling
4:33 Can we please just agree on "keratin"??
6:11 How shampoos and sulfates really work
10:27 Sulfates strip LESS?
11:01 Intentional product design
12:33 Foam?

Studies and links from the video:

🙋🏻 I'm Michelle, a chemistry PhD, cosmetic chemist and science educator, here to explain how beauty products work, debunk myths, and help you make smarter decisions about your skincare, hair and makeup!

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[LabMuffinBeautyScience]

I hope you enjoyed this video!

I didn't go into as much detail about water and hair as I wanted since it wasn't as strongly related to sulfates, but I did get to finally go into a bit of supramolecular chemistry which was my favourite part of my PhD 😊

What other hair topics would you like me to talk about?

[shusju]

We would really appreciate a serie on hair science covering different topics

[Sebastian-xyxk]

As somebody with curly/wavy hair, I have found that detangling my hair when it's wet tends to cause less breakage when paired with a conditioner. If I brush my hair dry, it tends to snag a lot more and I end up looking puffy. Silicone rich conditioners are the best at reducing breakage.

[lucyoconnor]

Another factor is the kind of water you have. That has a significant impact, especially if you colour your hair.

[hannahshark]

Hair Stylist here. Thanks for this video, it's so hard to choose a brand or product line to stock in a salon because it can work beautifully on 80% of clients but do nothing or worse on the remaining 20%. Hair products are a nightmare to shop for and ingredient lists tell us nothing. It's very expensive because you have to actually try each one on multiple people, usually staff first 🤣

[flowerhairgirl]

Misinformation in the health/beauty space really really frustrates me, particularly influencers "educating" with absolute shameful confidence on products based off no scientific reasoning or evidence whatsoever. I'm always relieved to see videos like this where someone is actually using REAL SCIENCE with genuine scientific qualifications to explain products properly.

[liznotslow]

Another complication for shampoo is water hardness. I tried SO MANY shampoos to find my favorites. Then last year I moved and the water is so much harder. And my favorite shampoos perform so poorly now. And my hair is acting different because I think there is more mineral build up on it because of the hard water. It’s just all dizzyingly complex!!

[margaesperanza]

Hair science and culture is wild. I was once bullied in a beauty subreddit when I told people I shampoo everyday because my hair gets oily fast and my country is tropical and humid. Another instance is that I know women who sell their hair to be made into expensive wigs, and all they use is cheap shampoo that they wash daily. Granted I know Americans are a dominant demographic in most English-language forums but it does get tiring trying to talk about nuance of beauty and hygene on a cultural scale.

[ioanaschifirnet]

I mean this in the best of ways - realizing how little we actually know gives me anxiety but also makes me feel less crazy! Because so many other people act as if they’ve cracked the code and they really haven’t! We definitely would like as many hair videos as you’re able to make!!

[Channotek]

as a hairstylist, this was HUGELY interesting. i would LOVE to hear your thoughts on the science of Olaplex, K18, and other bond builders!!!

[LethalLemonLime]

Omg thank you for talking about the differences!! There's another cosmetic chemist who just straight up DENIES the difference between straight hair and kinky hair even though it's blatantly obvious. I remember growing up and seeing people with straight hair swim and how their hair would stick together when wet. I'm not a scientist but with my own eyes I could see that. My kinky coily hair does not do that ever! And like you said, our hair being wet helps us detangle and manipulate it better and with less breakage due to less combing force DESPITE the fact that water breaks the hydrogen bonds and weakens the core. Too many hair care people refuse to see nuance. Trying to detangle my hair dry will leave me bald. So even though hair is technically weaker when wet, doesn't mean that it's better and safer to comb it dry.

[JenniferNoelle]

This was really perfect timing because I've been trying to figure out hair stuff again lately. I just saw a video where a guy said you HAVE to shampoo twice and you HAVE to buy the professional shampoo because the drugstore stuff is watered down and won't do anything for you. Plus, I still see controversy about whether or not you should wash your hair everyday or not. While I'm skeptical about having to spend more to get a good shampoo, I wish I had some real answers from someone I trust! Thanks for this video, it was a good start to my search.

[rubbish_kat]

the amount of conflicting information that gets spread around about haircare products is truly staggering, even among people you'd think are qualified like hairdressers, one minute an ingredient is good and necessary, the next it's evil and will make all your hair fall out. So well informed and science based information like this is so helpful.

[SchlichteToven]

Haha, combing curly hair while wet finally has the science behind it explained! I had straight hair till about 13, and it was really hard to brush when it was straight. Then it changed to about 3A curls, I think they're called. People would always give hair advice that was meant for straight-haired people, like you need to comb your hair every day! Which was hugely difficult and broke combs, then turned my hair into a giant puff. Combing while wet - no problem!

[nitzeart]

This is a pretty good start to hair science! You have to do a video on the poor demonized silicones haha
I know you did a blog post about quats and cationic surfactants, but if you can, I would love to hear more about them and about conditioners in general, and how effective they are vs leave-on conditioning products. I'm also curious about the science behind "heat protectant" products. I have my doubts about whether they actually do anything. (Oh I also saw somewhere that drying your hair with a hairdryer makes it last longer without oils, prologuing the time between washes. I think there's like one single study on it though.)

Salon vs drugstore formulas/products would be a good topic too, as so many hairstylists want to sell you their expensive products so bad and they sunk on drugstore ones so much (as if everyone had the income to buy the expensive counterparts).

[breannaflores]

When it comes to hair products in general there’s also the factors of hair density (amount of hair), coarseness (thickness of the individual hair strands), porosity (how much the cuticles lift for water to go in/ out of the strands). Plus then there’s still the scalp itself like oil production or if you have dandruff. The battle for finding hair products that work for you never ends 😅😅

[thegreenmanofnorwich]

I'm an admin on a men's long hair group. People get stressed about "you must do this!" "Never do that!" Etc. My approach is always to just go with what works at the time. The only caveat I put in is that if you want to grow very long hair, then you have to be really really kind to it as the hairs age. That said, with shoulder-ish length hair, if someone wants to washbwith clarifying shampoo every day and that works for them, then to go for it.

[frozenyogurth]

This is kinda off topic, but I absolutely ADORE your background. Like, the lego flower, the volumetric flask with the fairylights, the molecule model. It's all just *chef's kiss*

[stagnantfox]

Being a professional hairdresser who prides himself in the chemical aspect of my career I have to admit that even I fell for the "SLS/SLES is really bad for you" mindset. Unfortunately no job comes with the guarantee that there wont be some sort of bias due to how the people who pay us influence our perceptions. That aside, glad to see people smarter than me cover these topics, what we are taught at school is incredibly limited despite my school being really good (I studied in Sweden).

[Yorea]

From now on I'm going to call surfactants "pink tadpoles".
On a serious note, I love this video and it confirms what I thought about the whole shampoo and conditioner stuff. I have curly hair and have encountered the "Curly girl method" plenty, tried it for a year, and found that it did nothing for my curls with more effort than usual. Besides them recommending going sulfate free, they also don't want silicones because allegedly they don't come out without... sulfates! Well, I now use a sulfate free shampoo (just because it happens to be, not intentionally) with a silicone conditioner and I'm doing just fine.
I hope you'll do more hair videos! Because this was so interesting!!