SULFONATED KERATIN is graded A (Safe) by Expert·ING, based on COSING regulatory data.

SULFONATED KERATIN

Safety grade: A

Sulfonated keratin is a processed form of keratin, the same tough protein found in hair and nails, that has been chemically modified to work better in cosmetic products. It helps strengthen and protect hair and skin by forming a protective layer.

This ingredient is used to condition hair, protect skin, and create a thin protective film on the surface of hair and skin that helps retain moisture and improve appearance.

Graded using: COSING.

Last verified: May 26, 2026