What is Sulfate? Understanding Sulfates and Sulfate-Free Products

Emma Sarran Webster

Does it ever feel nearly impossible to shop for beauty products without getting worried and overwhelmed about all the ingredients inside them. Like sulfate, for example. What is sulfate, anyway? We talked to top scientists and doctors to get to the bottom of the issue. Read on to learn exactly what sulfates are, how they work, if we should be avoiding them, and more.

What is Sulfate?

Sulfates are detergents, or surfactants, commonly found in products like shampoo, body wash, face cleanser, and toothpaste (in addition to household cleaning products, like laundry and dish detergent). The most common sulfate-based ingredients found in personal care products are sodium lauryl sulfate and sodium laureth sulfate. "Sulfates act on the hair surface to remove dirt, sebum, and other product residues, and they also have properties that enable lather," explains Pantene senior scientist Rolanda Johnson Wilkerson, PhD.

“Sodium lauryl sulfate is a degreaser in a sense. It allows for the food particles to be aided in their transition from our mouth, helping to achieve that ‘clean' feel. It gives that nice foaming action that we are known to get while brushing," adds Karen Fields-Lever, a dentist based in Chicago.

Sulfates, which have been in used in personal-care products since the 1950s, are "the most commonly used detergents in the beauty industry," says cosmetic chemist Perry Romanowski.

Why are Sulfates Bad for You?

The biggest issue with sulfates is that they can cause varying levels of skin and eye irritation, which (for the people who experience it) gets worse the longer the product is in contact with the skin. "Sulfates can often dry out the skin, and some people find they may lead to more acne when their skin is in frequent contact with sodium lauryl sulfate,” explains David Lortscher, M.D., a board-certified dermatologist and cofounder and CEO of Curology. “This is typically less of a problem with body skin [versus face skin], so most people tolerate sodium lauryl sulfate in body washes."

Sulfates in toothpaste could also potentially be to blame for some symptoms inside your mouth as well. “Sodium lauryl sulfate can cause or irritate existing allergies, canker sores, and bad breath,” Dr. Fields-Lever says. And, she notes, "there are some professionals [who] feel sodium lauryl sulfate can be harmful to the mucosa [gums and cheeks] of the mouth."

What Does Sulfate Do to Your Hair?

When it comes to hair products, the concern has to do with the state these detergents may leave your locks in. When used in shampoos, sulfates are very efficient cleansers—maybe a little too efficient—and can pull a lot of natural oil from hair and skin. They’re so good at cleaning that they can actually strip your hair of its natural oils and make it feel rough, dry, and brittle. They can also cause dryness and irritation on your scalp.

It's a common misconception that sulfates affect color-treated hair. "It's a myth that sulfates will strip hair color," Romanowski says. "They don't strip the color any worse than any other shampoo detergent."

Lortscher also notes that hair-care products with sulfates may contribute to acne around your hairline or acne on your back (which is exposed to hair products in the shower), while toothpastes with sulfates may lead to skin issues in areas that come into contact with foam.

Do Sulfates Cause Cancer?

There was a time when people thought sulfates caused cancer. “The perception that sodium lauryl sulfate is carcinogenic appears to have arisen in the early 1990s,” Dr. Lortscher says. But, he notes, those claims have been disproven. “According to a review of the toxicity of sodium lauryl sulfate in humans and in the environment published in 2015, this false claim is thought to have derived from multiple misinterpretations of the scientific literature. sodium lauryl sulfate is not listed as a carcinogen by the International Agency for Research on Cancer, the U.S. National Toxicology Program, California Proposition 65 list of carcinogens, the U.S. Environmental Protection Agency, or the European Union.”

Dr. Lortscher also notes that the independently operated Cosmetic Ingredient Review Expert Panel (which is funded by the Personal Care Products Council) has deemed sodium lauryl sulfate to be safe for brief use on the skin (meaning in products that you rinse off shortly after applying).

Sodium Lauryl Sulfate vs. Sodium Laureth Sulfate

"Sodium lauryl sulfate is a slightly more aggressive surfactant and will tend to clean surfaces better,” Romanowski says. “It also has a better foam profile. Sodium laureth sulfate is a milder version, so it is not as irritating, but it doesn't clean as well, either."

That being said, it doesn’t have to be one or the other. “Often formulators include both to get the cleaning power of sodium lauryl sulfate and reduced irritation level of sodium laureth sulfate,” Romanowski says.

Dr. Lortscher notes that sodium laureth sulfate is often used in skin and hair products because it imparts a high degree of foaming capacity to the product and a feeling of softness on the skin. And, he says, “if you tend to get clogged pores or acne breakouts, read labels and avoid sodium lauryl sulfate in skin and hair-care products. It appears that sodium laureth sulfate and sodium lauryl ether sulfate may be less likely to incite acne.”

Should I Use Sulfate-free Shampoo, Body Wash and Other Products?

If you're looking for a bubbly lather and that squeaky clean feeling, sulfates are your friend! Johnson Wilkerson says that today's beauty brands are generally careful to use a combination of sodium lauryl sulfate and sodium laureth sulfate that is "very suitable and safe for mild and gentle cleansing."

If, however, you have sensitive skin or just want to avoid them completely (and that's totally fine too!), just remember that those sulfate-free products won't probably won't foam up, so they'll produce a more hydrating, creamy wash

“Sodium lauryl sulfate is a foaming agent, and when it's taken out, your cleanser won’t make suds like you might be used to,” Dr. Lortscher says.

Lathering, however, is not an indication of your shampoo's effectiveness. Just because it doesn’t lather doesn’t mean it doesn’t clean (think makeup remover). But if you use a lot of styling products or have very greasy hair, a lathering cleanser with a more detergent-like effect is necessary to remove product and oil from the hair.

What about sulfate-free toothpaste? "There is not currently a substance that has been developed that gives the ‘foamy action’ that sodium lauryl sulfate delivers in its replacement,” says Dr. Fields-Lever. “Nonetheless, some manufacturers are replacing sodium lauryl sulfate with oils such as palm oil, olive oil and coconut oil to eliminate bacteria. Although these do not provide the soapy-suds effect, they do aid in a cleaner mouth after brushing.”

Are "Sulfate-Free" Products Just a Marketing Ploy?

It is not generally thought that sulfates are dangerous to your health, and Romanowski suggests the movement to keep them out of products isn’t driven by safety. “The beauty industry doesn't believe that sulfates are dangerous,” he says. “There are some marketers who are convinced that consumers believe the ingredients are dangerous, and they have used that fear to sell their own products. It's only recently, within the past 15 years, that large companies have advertised sulfate-free products." Now, as Romanowski previously mentioned, they're still extremely common in personal-care products.

That said, there is the issue of irritation, which may or may not affect you. “Everyone’s skin is different, and individual responses vary,” Dr. Lortscher points out. If you do find yourself with skin or eye issues and you’re using products that contain sulfates, there’s certainly no problem with seeking out sulfate-free substitutes.

How to Check to See if Your Products are Safe

You can use tools like the EWG’s Skin Deep database, which rates more than 70,000 personal products based on known and suspected hazards of ingredients and available scientific studies about those ingredients, to find and learn about alternatives.

And if you’re unsure about what you see on a label or online, you can always consult your primary-care doctor or dermatologist for their professional opinion. The most important thing is to think beyond the splashy claims in advertisements and on product packaging and focus on what the ingredients listed on the back mean — and fortunately, the aforementioned resources can help you do that without getting too overwhelmed.

Related: Why Parabens Could Be Bad for You

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Originally Appeared on Teen Vogue