Gamma polyglutamic acid is a high-molecular-weight biopolymer produced by Bacillus fermentation of glutamic acid. It's used in serums and masks to attract and hold water on the skin surface, add slip, and support a supple feel.
Not typically evaluated for comedogenicity — no standardized rating available.
Our take
Is Gamma Polyglutamic Acid a Good Ingredient?
It rates Great because it's a stable, water-soluble humectant with supportive in-vivo hydration data and low irritation potential, and it genuinely improves moisture retention and skin feel. It also layers well with other actives across typical cosmetic pH ranges, which is the kind of consistent, well-supported performance that earns the top rating.
What it does
Skin Benefits
Delivers long-lasting surface hydration for a plumper, smoother feel and helps reduce tightness. Can minimize the look of fine flakiness from dryness.
Where you'll find it
Uses in Skincare & Cosmetics
Featured in hydrating serums, sheet masks, and moisturizers to boost water retention and provide a silky application.
Before you use it
Safety
Generally very well tolerated with low irritation potential. Rarely, tackiness or pilling may occur at higher levels or when layered with certain products.