POLYLYSINE is graded A (Safe) by Expert·ING, based on COSING, FDA regulatory data.
POLYLYSINE
Safety grade: A
Polylysine is a chain of amino acids (the building blocks of proteins) that helps hair retain moisture and adds shine. It works by coating the hair shaft to smooth and protect it.
This ingredient conditions hair by forming a protective layer that reduces frizz, improves softness, and enhances shine while helping hair retain moisture.
Graded using: COSING, FDA.
Last verified: May 26, 2026
Other Hair Conditioning ingredients
- GLYCERIN — Grade B
- COCAMIDOPROPYL BETAINE — Grade A
- PANTHENOL — Grade A
- CAPRYLYL GLYCOL — Grade A
- SALICYLIC ACID — Grade C**
- CYCLOPENTASILOXANE — Grade C**
- BEHENTRIMONIUM CHLORIDE — Grade A
- MALTODEXTRIN — Grade A