In cosmetics, this large group of ingredients is used mainly as cleansing agents in skincare and hair-care products; they include sodium lauryl sulfate, ammonium lauryl sulfate, and sodium laureth sulfate. Many consumers are concerned of sulfates in their cosmetics products because of widespread misinformation. Sulfates are not a problem, but once organizations and companies build up fears among consumers about certain cosmetics ingredients there’s almost no going back, the damage is done.
In reality there’s absolutely no research showing that sulfates are a problem in skincare or hair-care products, other than causing sensitivity, but that is also true for the sulfate-free cleansing agents that some cosmetics companies advertise and sell. And, whether or not a cleansing agent will cause sensitivity depends on the amount of sulfate and on other ingredients present in a specific formula.
Following are some of the most typical unsupported comments about sulfates: “Sulfate-free shampoos and cleansers are better for hair and skin.” No research has shown that to be even remotely the case. Sulfates are supposed to be terribly drying and damaging to hair, when in fact they function no differently from the cleansing agents in sulfate-free shampoos. Almost every company that touts the fact that they don’t contain sulfates do use detergent cleansing agents such as sodium lauryl sulfoacetate, disodium laureth sulfosuccinate, sodium lauroyl sarcosinate, cocamidopropyl hydroxysultaine, sodium cocoyl isethionate, cocamidopropylamine oxide, and sodium methyl 2-sulfolaurate.
Why those are supposedly any better for skin is never explained, and no research is ever cited—because none exists. Sometimes these companies list those ingredients as being derived from or coming from coconut to make them sound natural and, by association, better for skin—but they all end up being primarily synthetic. That doesn’t make them bad in any way; it’s just that the claims are completely disingenuous. What you need to know is that both the sulfate-free cleansing agents and the sulfate versions can be drying and sensitizing depending on the formulation and/or your skin’s own reaction. All of these cleansing agents remove oil and the gunk from styling products, which is exactly what a shampoo should do.
“Sulfates in cleansers are cheap.” This one is true, but so what? Lots of ingredients, both natural and synthetic, are cheap, others are expensive, which has absolutely nothing to do with quality or efficacy. The first ingredient in sulfate-free shampoos is water (about 90% water) and no other cosmetic ingredient is cheaper than that!
“Sulfates are used in floor cleaners and are corrosive.” This can be true, when used in large amounts and when left on surfaces over time, but so what? Salt is used to melt ice on the roadway, but it also rusts cars, which doesn’t make salt bad; it just depends on how much you use and how long you leave it on something. This is also true for the alternative sulfate-free shampoos and cleansers as well; they can also be corrosive over time depending on how much is used and how long it is left on.
“Sulfates can be sensitizing.” This can absolutely be true, but again, so what? As a general category, sulfates are not sensitizing when used in appropriate amounts in shampoos and cleansers and the same is true for sulfate-free alternative cleansing agents. All of the research about sulfates being sensitizing are from patch tests where a concentration is left on skin under a bandage for 24 hours, which is not how a cleanser or shampoo is used. Sodium lauryl sulfate is considered one of the more sensitizing cleansing agents and we recommend avoiding it when it is high up on the ingredient list, but that’s NOT because it’s a sulfate; rather, it’s because of its interaction with skin.
In summary, not all sulfates are the same, and there are plenty of them that are completely safe and beneficial in skincare and hair-care formulations. More to the point, sulfate-free alternatives can also be extremely drying and sensitizing when left on skin for long periods of time under occlusion, but that’s not how they are used, either.
References for this information:
International Journal of Toxicology, July 2010, pages 151S-161S
Journal of Cosmetic Science, March 2009, pages 143-151
Journal of the American Academy of Dermatology, January 2005, pages 125-132
International Journal of Cosmetic Science, June 1999, pages 371-382
Environmental Health Insights, November 2015, pages 27-32
magnesium laureth sulfate
sodium laureth sulfate
sodium C14-16 olefin sulfonate
sodium cetearyl sulfate
ammonium laureth sulfate
magnesium oleth sulfate
sodium trideceth sulfate
ammonium lauryl sulfate
sodium lauryl sulfate