POLYEPSILON-LYSINE is graded A (Safe) by Expert·ING, based on COSING, FDA regulatory data.

POLYEPSILON-LYSINE

Poly-epsilon-lysine

Safety grade: A

Poly-epsilon-lysine is a natural antimicrobial compound made from amino acids that helps preserve cosmetic products and keep them fresh. It works by preventing the growth of bacteria and other microorganisms.

This ingredient conditions hair and skin while also helping to preserve the product by inhibiting microbial growth, making cosmetics last longer and stay safer to use.

Graded using: COSING, FDA.

Last verified: May 26, 2026