ACETYL SH-TETRAPEPTIDE-39 is graded A (Safe) by Expert·ING, based on COSING regulatory data.

ACETYL SH-TETRAPEPTIDE-39

Safety grade: A

This is a small protein fragment created in a laboratory that is designed to improve skin texture and appearance. It works by signaling skin cells to function more efficiently and maintain a healthy, smooth surface.

This ingredient conditions and improves the overall quality of skin by promoting a smoother, more refined appearance and supporting the skin's natural barrier function.

Graded using: COSING.

Last verified: May 26, 2026

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