Sodium Lauryl Sulfate (SLS), Sodium Laureth Sulfate (SLES) and Ammonium Lauryl Sulfate (ALS) get a bad rep all over. So the common gospel these days usually goes: Avoid sulfates! Opt for sulfate-free shampoos and hair care products! They are milder and will not dry out your hair.
But is that really?
I’ve been avoiding SLS for the past years, successfully. However, I found it close to impossible to forego SLES, so I continued using it.
(Of course now I finally know a couple of easily available shampoos without Sulfates entirely, but I’ll get to that later.)
I didn’t have much of a problem with SLES either. It did its job, and all was good. Until I noticed some dry flaking on my scalp. That’s when I started digging around.
So what are Sulfates really, what do they do?
Do You Need To Worry About Sulfates In Your Shampoo? on xoVain sums it up nicely, so I recommend you read that post first and then proceed.
But the bottomline is this: Sulfates are surfactants. Surfactants are cleansing agents, formulated to remove dirt and grease. And yes, their ability to remove grease also means they can be stripping. Stripping your scalp and hair from their natural oils, that is. So yes, Sulfates can be stripping.
However, other non-Sulfates surfactants work exactly the same way. Because that’s their primary function to begin with: remove dirt and grease. So if a surfactant doesn’t strip the hair, it probably also means it doesn’t cleanse it so well either. Surfactants have no way of discriminating between “good” and “bad” oils after all.
But of course, different surfactants are still different. Read How to pick a mild shampoo on The Beauty Brains or Essentials of Hair Care often Neglected: Hair Cleansing from the International Journal of Trichology on NCBI to see in what ways.
The most important aspect for the consumer, however, is how irritating they are.
And here I’ll make my point: Risk of irritation is a completely different problem from stripping hair and scalp!
Case in point #1: Sebamed Every Day Shampoo
So here is a drugstore shampoo – or at least in Germany, you can easily get it at every drugstore – that does not contain Sulfates. Formulated for sensitive, dry scalp, the Sebamed Every Day Shampoo with a pH of 5.5 contains:
Aqua, Decyl Glucoside, Disodium Laureth Sulfosuccinate, Sodium Lauryl Sulfoacetate, PEG-55 Propylene Glycol Oleate, Propylene Glycol, Hydroxypropyl Oxidized Starch PG-Trimonium Chloride, Sodium Citrate, PEG-18 Glyceryl Oleate/Cocoate, Parfum, Phenoxyethanol, Sodium Benzoate.
The individual surfactants in this shampoo are generally considered harsh. However, according to cosmetic chemist Stephen Ko here, even harsh surfactants such as SLS can be made gentler by mixing them with other surfactants, and by adjusting the pH of a product.
Reviews on this shampoo generally agree: This shampoo is great for itchy, dry scalp. But it dried out many users’ hair.
Huh, I thought, interesting. It is great for scalp, but not so much for the hair. Why?
The shampoo cleanses effectively as well as gently. It does not irritate the scalp. However, it barely contains any conditioning agents either. Nothing to replenish moisture or smoothness to the hair. That’s why users report great results for their scalp, but not so great results for their hair.
Case in point #2: Lush Fun bars
So I’m still using SLES, a Sulfate, on my hair. Basically, I even use almost pure SLES on my hair. Because I use and love the Lush Fun Bars as shampoo. And this is what they’re made of mostly:
Cornflour, Talc, Glycerine, Sodium Laureth Sulfate,
and then they also contain some essential oils, perfume and colors to give each bar its unique “flavor.”
Lush merely uses the cornflour and talc to achieve the Fun bars’ characteristic texture and tactile properties, while the essential oils, perfume and colors don’t really do much either. Glycerine is an effective humectant, which could be good for both scalp and hair, but in a rinse-off product does just that: rinse off. So really all that remains is the SLES.
Now I’d been skeptical and wary about SLES myself. It’s known to be irritating, it’s supposed to be drying… At least in my skin care products I’ve been avoiding it for a long time.
The Lush Fun bars have been delivering some of the best results on my scalp and hair so far. OK, they’re not great on my bleached ends, but: no flaking. And my hair is smooth and glossy when I use it. Tangled, yes, a little. Understandably, given the lack of conditioning agents in this too, but then also not wildly so.
And although I know this is only anecdotal evidence at best, why does it work so well for me?
A reddit conversation and a Google search
On my search for Sulfate-free shampoos that would be good on my dry scalp, one reddit user – who identified themselves as “Cosmetic Chemist” – wrote me this:
“Sulfates are likely not a worrisome problem if you have a dry scalp and normal hair, not to go all low tech but try head and shoulders. Sulfates get an unfair shake, its actually the EO/PO that de-fats and drys hair and scalps. This can be mitigated through proper formulation, but avoiding them is hard and expensive.“
So I looked into EO/PO. Which means I Googled it. And found EO stood for Ethylene Oxide, and PO for Propylene Oxide.
I couldn’t find that much about PO. But what I was able to deduce is that EO is a common by-product during the formulation of SLES and some other common skin care ingredients, such as PEG 40 Hydrogenated Castor Oil. It can also be found in fragrances.
Ethylene Oxide is what gives SLES its E, and there are “3 types of SLES that you can’t discern on a label and only a formulator would know. 1 molar, 2 molar and 3 molar which has to do with the moles of EO (eth) attached to the Lauryl group in the Sodium Laureth Sulfate,” according to aforementioned reddit user.
So what it eventually boils down to, at least as far as I understand it, is formulation.
So here’s my personal conclusions on Sulfates
If your scalp is irritated, it does make sense to switch to gentler products – Sulfate-free shampoos included. If your scalp is dry, however, that’s another question. In this case, it could or could not be the Sulfates.
Apparently, it strongly depends on the quality of the Sulfates themselves, as well as the overall formulation of the product you are using.
The reddit user mentioned above, for instance, recommended me Head & Shoulders shampoos for my dry scalp problem, which contain both SLS as well as SLES. However, they assured me Head & Shoulders use “a great system I didn’t design or formulate it but it is what sulfate shampoos always should be.”
Another example is from my own experience with the Lush Fun bars, which you could say are almost pure, albeit diluted, SLES – yet give me great results nonetheless.
So you really cannot generalize.
Last but not least, if your hair is dry and damaged, the main problem isn’t so much Sulfates either, but more what else is in your shampoo.
As I already said, you’ll want conditioning agents in your product because that’s what gives your hair slip, detangles it, makes it softer as well as more shiny. You can find a list of common conditioning agents in shampoos and conditioners under the “What do conditioners contain?” section in this article. If your shampoo doesn’t contain any of these, use a good conditioner.
So should you worry about Sulfates in your hair care?
You see now why it depends.
All things considered, however, I’d say that if you do find a hair care product that works for you, the fact that it may contain Sulfates is no reason for concern.
At least when it comes to your scalp and hair.
When it comes to your face, however, I still recommend avoiding harsh surfactants, including Sulfates, in your skin care. Because.