Common Name(s): Pga,poly-l-glutamic acid,natto gum

CAS Number: 25513-46-6

DESCRIPTION

What It Does: Provides 4-5× greater water retention than hyaluronic acid for unmatched skin hydration.

Why It's Used: The most powerful humectant available – 4-5× the water-binding capacity of ha – for formulations requiring maximum hydration intensity in a single ingredient.

How It Works: High density of free glutamic acid carboxylate groups provides exceptional water binding capacity (~5000× its dry weight in water, vs ha's ~1000×). forms thin hydrating film on skin surface. inhibits hyaluronidase, protecting endogenous ha from degradation. also promotes ha synthesis.

Typically Found In: Premium hydrating serums,ultra-hydration products

TECHNICAL DETAILS

Primary Category: Active ingredient – microbial humectant

Secondary Functions: Maximum water retention,ha protection,film forming

Application Areas:

Typical Concentration Range: 0.1%–5%

SOURCING & ETHICS

Vegan Status: Yes – bacillus subtilis fermentation

Halal Status: Yes

Source Notes: Synthetic or naturally derived. excellent aqueous solubility.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; suitable for all skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Ceramides,emollients,occlusives,glycerin,hyaluronic acid

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Pga's water-holding capacity of ~5000g water/g pga (vs ha's ~1000g water/g) derives from its exceptionally dense carboxylate group array. the glutamic acid polymer backbone provides a carboxylate group every ~0.37nm along the chain – the highest density of water-binding anionic groups achievable in a linear biopolymer structure.

Last Verified: 2026-03-12

Primary Sources: Cosing database,shen et al. polyglutamic acid cosmetic review