TETRAPEPTIDE-55 is graded A (Safe) by Expert·ING, based on COSING regulatory data.

TETRAPEPTIDE-55

Safety grade: A

This ingredient is a lab-created protein fragment made of four amino acids linked together. It's designed to help improve skin's firmness and elasticity by supporting the skin's natural structure. You'll find it in anti-aging and lifting creams, where it works to reduce the appearance of fine lines.

Graded using: COSING.

Last verified: June 9, 2026