Cleansing Agent

Sodium Isethionate

Reviewed by Rosie · Last updated 18 Aug 2026

Also known as: sodium 2-hydroxyethyl sulfonate

Used as a surfactant | Becomes a detergent when it contacts oleic acid

Addresses

Cleansing, Surfactant, Foaming Agent

What Is Sodium Isethionate?

Sodium isethionate, also known as sodium 2-hydroxyethyl sulfonate, is a synthetic ingredient used as a surfactant (surface active agent) in cosmetics. Surfactants interact with both water and other substances like oil and dirt, allowing them to act as detergents and foaming agents (they also help substances spread more easily). Sodium isethionate in particular forms a mild detergent when it comes into contact with oleic acid. Detergents are a type of surfactant, but otherwise the term “surfactant” has a broader meaning. The independent Cosmetic Ingredient Review board has ruled sodium isethionate safe as used in cosmetics, where its maximum usage concentration range is between 0.8%-6%.

Clinical Evidence & References

Published Research

  • PubChem, Website, Accessed April 2025 [https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-Isethionate]
  • Ataman Chemicals, Website, Accessed April 2025 [https://www.ataman-chemicals.com/en/products/sodium-isethionate-6272.html]
  • International Journal of Toxicology, May-June 2017, pages 5S-16S [https://journals.sagepub.com/doi/10.1177/1091581816685552]

Frequently Asked Questions

From the Clinic

Not sure what your skin actually needs?

Two minutes, a few questions, and we’ll point you at what matters — no guesswork.

Take the skin quiz

Learn More About Skincare Ingredients

Explore our comprehensive ingredient glossary to understand what's in your products.

Browse All Ingredients

Authorised Stockist

Official UK retailer

Tracked Delivery

Free UK shipping over £50

5 Star Rating

Trusted by thousands

Expert Advice

Free consultations