What it is
Acetyl Carnosine is a stabilized, acetylated derivative of carnosine, a naturally occurring dipeptide of beta-alanine and histidine. In cosmetic formulas it is used as an antioxidant and skin-conditioning agent, valued because the acetyl group can improve stability relative to free carnosine. It appears in serums and sunscreens as a supporting antioxidant ingredient.
Safety & warnings
Peptide-based antioxidants like acetyl carnosine are generally well tolerated in topical use and are not associated with significant irritation or comedogenicity at cosmetic concentrations.
Origin & sourcing
Synthetic or biosynthetic; it is the acetylated form of the dipeptide carnosine, which occurs naturally in the body, prepared for cosmetic use.
Questions everyone asks
How is acetyl carnosine different from carnosine?
It is carnosine with an added acetyl group, which can improve the molecule's stability in a cosmetic formula.
What does it do in a sunscreen?
It acts as a supporting antioxidant and skin-conditioning ingredient, not as a UV filter.