TETRAPEPTIDE-121 is graded A (Safe) by Expert·ING, based on COSING regulatory data.

TETRAPEPTIDE-121

Safety grade: A

This laboratory-created protein fragment works to support your skin's natural firmness and elasticity by helping strengthen the structure beneath the surface. It's designed to help reduce the appearance of fine lines and keep skin looking smoother and more resilient over time.

Graded using: COSING.

Last verified: June 9, 2026