Sulfates in Shampoo: Should You Avoid Them?

Katelyn Hagerty

Reviewed by Katelyn Hagerty, FNP

Written by Our Editorial Team

Published 01/15/2018

Updated 04/12/2023

Ever wondered why shampoo quickly turns into foam when mixed with water? The answer, for many supermarket shampoos, is the inclusion of chemical foaming agents like sodium lauryl sulfate and sodium laureth sulfate.

Known commonly as sulfates, these ingredients help shampoo mix into water, creating the foamy texture — the lather — you get when you massage shampoo into your hair and scalp. Sulfates are commonly found in mass-market shampoos, including most of the brands you’ll find in your local supermarket.

At low concentrations, sulfates are considered safe to use. However, frequent use of products with a high concentration of sulfates may lead to buildup, which can contribute to cell damage and excess stripping away of natural oils and hair proteins.

From a hair care perspective, this definitely isn’t a good thing. In this guide, we’ll look at how the most commonly used shampoo sulfates can affect your hair, as well as the key reasons why you should avoid shampoos that contain chemical sulfates.

What Are Sulfates in Shampoo? 

From a chemical perspective, sulfates are surfactants. Their job is to reduce the level of surface tension between your shampoo and your skin, allowing the active ingredients in the shampoo to do a more effective job of cleaning dirt, oil and dead skin from your scalp and hair.

A variety of products contain sulfates, from shampoo to liquid dish soap and laundry detergent. When used in shampoo, ingredients like sodium lauryl sulfate and ammonium laureth sulfate amplify the shampoo's effects, allowing it to strip away more of the things that make your hair oily and uncomfortable.

Are Sulfates in Shampoo Bad for Hair?

Sulfates are “good” in the sense that they make shampoo far more effective. But they’re bad in the sense that they can have too much of a cleansing effect on your scalp and hair, resulting in excess stripping away of naturally occurring proteins and oils.

There have also been rumors over the years that sulfates (including sodium lauryl sulfate, the most common sulfate in hair products) can potentially cause cancer.

Luckily, these rumors aren’t backed up by any scientific evidence. The sulfates used in shampoo and other hair care products are not known carcinogens, and there are currently no scientific studies that show any link between sulfates and cancer.

Still, sulfates can potentially cause damage to your hair when overused, ranging from hair protein removal to irritated, itchy skin. So, will those sulfates kill you? Probably not. But can they kill your hair? Well…

Buy finasteride

more hair... there's a pill for that

What Does Sulfate Do to Your Hair?

At this point, we've mentioned the effects of sulfates on hair, and you don’t have to be a cosmetic chemist to understand that healthy hair and product buildup don’t mix. Now we’re ready to dive into just how bad they are.

Sulfates can cause a range of damage to your hair. For starters, they can trigger protein removal and contact dermatitis — the former, a long-term problem, and the latter, a short-term one. These cleansing agents can contribute to problems like dryness and require a dermatological intervention with medicated shampoos and skincare agents to address.

But let’s dig deeper on this.

Sulfates and Hair Protein Removal 

Hair is made of protein — in fact, hair itself is a protein filament. When the protein that makes up each of your hairs is damaged, it can weaken the hair, affecting its strength and appearance.

Sulfates are closely linked with damage to hair protein because, along with the grime, these cleansing agents can also wash away your healthy hair — almost literally. 

One study from 2005 showed that hair immersed in a sodium dodecyl sulfate solution loses two times as much protein as hair immersed in water. This can lead to split ends, breakage and hair that’s difficult to manage.

This problem may affect different hair types differently — fine hair and color-treated hair might be more susceptible than curly hair.

Because of this, sulfates are best avoided if you want to optimize your hair’s health, appearance and strength.

Sulfates and Contact Dermatitis

As a dermatology professional will tell you, sulfates not only strip hair protein. In some people, they can cause severe skin irritation and a painful allergic rash — a condition called contact dermatitis.

Studies suggest that people with low levels of ceramides — a type of waxy lipid molecule found in your skin cells — are more likely to experience skin irritation and contact dermatitis after exposure to sulfates such as sodium lauryl sulfate.

Not everyone will experience skin rashes or dermatitis after using shampoo or conditioner that contains sulfates. Still, it’s best to avoid shampoos that contain sulfates just in case, as there’s nothing fun about dealing with a scalp rash and the resulting itchy scalp.

Will you join thousands of happy customers?

4.5 average rating

Before/after images shared by customers who have purchased varying products, including prescription based products. Prescription products require an online consultation with a healthcare provider who will determine if a prescription is appropriate. These customers’ results have not been independently verified. Individual results will vary. Customers were given free product.

Do Sulfates Cause Hair Loss? 

No, sulfates do not directly cause hair loss. While sulfates aren’t directly linked to male pattern baldness, they’re best avoided if you have sensitive skin or naturally thin hair.

As we’ve covered before, a combination of hormones and genetics cause male pattern baldness — namely, a genetic sensitivity to something called dihydrotestosterone, or DHT. Sulfates aren’t currently known to affect scalp DHT levels and, as such, aren’t directly linked to pattern hair loss in men.

However, sulfates can be indirectly linked to male hair loss. If you’re susceptible to skin irritation from sulfates, you could temporarily lose hair as a result of irritation, turning those particular cleansers into hair loss shampoos. It’s also possible for protein loss from excessive exposure to sulfates to weaken your hair, making breakage more likely.

Hair loss treatments, delivered

Most popular

Topical Finasteride

If a pill feels like an overwhelming way to treat male pattern hair loss, this spray with finasteride & minoxidil could be for you.

Minoxidil Solution

Generic for Rogaine®, this FDA-approved over-the-counter version of topical minoxidil is used for regrowth on the crown of the head.

Finasteride & Minoxidil

This is the FDA-approved dynamic duo. When used together, men saw better results in clinical trials compared to using either alone.

Oral Finasteride

If you’re looking for something effective but don’t want too many steps in your routine, this once-a-day pill could be right for you.

Minoxidil Foam

Clinically proven to regrow hair in 3-6 months, no pills required.

The Verdict on Sulfate in Shampoos

If you’ve made the decision to avoid sulfates, you’re in luck: reducing your level of exposure to sulfates is simple — just switch from your current shampoo to a sulfate-free option. 

But there are some takeaways we’d like to leave you with before you go trashing stuff in your bathroom:

  • Compared to sulfate-based shampoos, sulfate-free shampoos can feel a little different. There’s less of a foaming, bubbling effect, meaning it can require some extra water to rinse sulfate-free shampoo from your hair.

  • Sulfate-free shampoos can also feel less intense, meaning you may not get the “cleansed” feeling you would from a typical shampoo. The shampoo is still effective, but the lack of foaming chemicals can mean it doesn’t have such a pronounced feel on your scalp.

  • It’s also worth reading the ingredient label on your other products — from body wash to toothpaste and conditioner — as many mass-market conditioners use ingredients like sodium lauryl sulfate or sodium dodecyl sulfate.

Sulfate-free products like our hair thickening shampoo, our volumizing shampoo, or our dandruff zinc shampoo are great options to start with. 

One final word: switching your shampoo isn’t all you can (or should) do. You may also want to explore other forms of hair loss treatment to supplement your shampoo.

2 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

  1. de Cássia Comis Wagner, R., & Joekes, I. (2005). Hair protein removal by sodium dodecyl sulfate. Colloids and surfaces. B, Biointerfaces, 41(1), 7–14. https://pubmed.ncbi.nlm.nih.gov/15698750/.
  2. Bondi, C. A., Marks, J. L., Wroblewski, L. B., Raatikainen, H. S., Lenox, S. R., & Gebhardt, K. E. (2015). Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS): Evidence for Safe Use in Household Cleaning Products. Environmental health insights, 9, 27–32. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651417/.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.