Common Name(s): Sodium polyglutamate (gamma-pga),natto bacillus ferment humectant,5000x water retention superior humectant
CAS Number: N/a
DESCRIPTION
What It Does: Provides the highest water-holding capacity of any commercial cosmetic humectant (5,000x), forms a uniquely smooth skin film from the polyamino acid backbone's sc protein complementarity, and delivers glass-skin ultra-hydration at low use concentrations.
Why It's Used: Gamma-pga's 5,000x water retention from double-carboxylate polyanionic architecture represents a step-change from conventional humectants — the donnan osmotic pressure from dense polyanionic charge immobilises water thermodynamically, not just hygroscopically.
How It Works: Poly-gamma-glutamic acid backbone provides two -cooh groups per residue (pka ~2.1 and 4.1) providing strong polyanionic character at ph 5-7. donnan equilibrium from the high ionic charge creates osmotic pressure that immobilises water molecules in the polymer matrix at 5,000x weight-for-weight. mw 50,000-1,000,000 da enables viscoelastic film formation on skin.
Typically Found In: Glass skin serums,premium hydration,k-beauty anti-aging
TECHNICAL DETAILS
Primary Category: Functional ingredient – humectant
Secondary Functions: Tewl reduction,skin plumping
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.1%–3%
SOURCING & ETHICS
Vegan Status: Yes
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
Gamma-pga biodegrades to l-glutamic acid — providing both complete environmental biodegradability and a nutritive degradation product contributing to skin amino acid availability. one of the highest sustainability scores among commercial humectants.
Last Verified: 2026-03-12
Primary Sources: Cosing database,sodium polyglutamate gamma-pga natto bacillus review