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Sodium lauryl sulfate (found in many shampoos) causes cancer

What you may have heard

Shampooing with products that contain SLS causes cancer.

What science tells us

SLS is a cleaning agent and surfactant that is used in many personal care and cleaning products.

Epidemiological Evidence

While SLS chemicals may cause eye irritation (or eye damage in high-enough quantities) and skin irritation when it stands alone, there is no evidence either way about whether sodium lauryl sulfate is a carcinogen. This has been confirmed by numerous government and international agencies, such as the International Agency for Research on Cancer (IARC), the U.S. National Toxicology Program, the California Proposition 65 List of Carcinogens, the U.S. Environmental Protection Agency, and the European Union (Bondi et al.).

Laboratory Evidence/ Supportive Evidence

Several laboratory-based studies conducted on mice showed signs of skin irritation but did not show a cancerous effect when exposed to sodium lauryl sulfate (Rovira et al.). 

 IARC Carcinogen Classification: Not classified

How to reduce your risk

While SLS may not be cancer causing, to avoid any skin or eye irritation, experts suggest switching to products that do not contain these chemicals. A number of websites, such as the Environmental Working Group’s Skin Deep Database or MADE SAFE, rate the safety of ingredients used in personal care products; these websites also post lists of brands that contain each type of chemical.

Shampoos that do not contain SLS are clearly marked on the label and can be located in any supermarket or pharmacy. A dermatologist and/or pharmacist may also be able to direct you to products that do not contain chemicals you wish to avoid.

Bottom line

SLS is not a carcinogen, yet there are many platforms that provide information and alternative products if the chemical causes eye or skin irritation.

Bondi et al.: Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS)
Environmental Working Group (EWG): Skin Deep Database
Snopes: SLS and Cancer


Published: July 9, 2021
Verified/updated: August 22, 2022