What it is
Ascorbic Acid Polypeptide is a derivative that pairs ascorbic acid (vitamin C) with a peptide moiety, an approach intended to improve handling and stability relative to pure ascorbic acid. In cosmetic formulas it is used as a skin-conditioning agent and is associated with antioxidant character typical of vitamin C derivatives. In sunscreens it appears as a supporting ingredient rather than a UV filter.
Safety & warnings
Vitamin C derivatives are generally well tolerated, though pure ascorbic acid at low pH can be irritating; bound derivatives are often chosen for milder handling. It is not a recognized fragrance allergen or notably comedogenic. Individuals with very sensitive skin may patch test.
Origin & sourcing
Synthetic derivative; produced by chemically combining ascorbic acid with a peptide component.
Questions everyone asks
Is this the same as plain vitamin C?
Not exactly. It is a derivative in which ascorbic acid is attached to a peptide, intended to ease formulation while retaining vitamin C character.
What does it do in a sunscreen?
It serves as a conditioning, antioxidant-type ingredient; it does not provide UV filtration.