Sodium Cocoyl Isethionate

What is it?

A mild, coconut-derived anionic surfactant widely used in "syndet" (synthetic detergent) cleansing bars as a gentler alternative to soap and sodium lauryl sulfate.

What does it do?

According to PubMed, a 1999 study comparing the skin-damaging effects of 8 surfactants found sodium cocoyl isethionate caused less irritation (erythema, transepidermal water loss) than sodium lauryl sulfate and several other tested surfactants (DOI: https://doi.org/10.1111/j.1600-0536.1999.tb05999.x). A second 1999 irritancy-ranking study using repeated exposure methods found sodium cocoyl isethionate was less irritating than sodium lauryl sulfate and soap, though more irritating than a sulfosuccinate-type anionic detergent, across repeated occlusive and open-test methods (DOI: https://doi.org/10.1111/j.1600-0536.1999.tb06082.x).

Sources