biotech
Polyglutamic Acid (PGA)
Quietly positioning itself as hyaluronic acid's successor — or its superior partner. Produced by fermentation of glutamic acid by Bacillus subtilis, PGA can hold up to 5,000x its weight in water (vs. ~1,000x for HA). Its high molecular weight (~2,000 kDa) forms a protective film that physically slows transepidermal water loss, and it inhibits hyaluronidase, extending the lifespan of skin's own HA reserves.
Benefits
- holds up to 5,000x its weight in water
- forms a film that seals in moisture
- inhibits hyaluronidase to preserve native HA
Example uses
- hydrating serums
- toners
- eye creams
- plumping moisturizers
Mechanism of action
A linear poly-amino-acid produced by Bacillus subtilis fermentation (the same metabolic platform that produces natto's characteristic stringy texture). The polymer is essentially repeating L-glutamic acid units linked through γ-carboxyl groups; the resulting carboxylate-rich, high-molecular-weight (1–2 MDa) structure binds water at exceptional capacity (theoretical 5,000× by mass, in-use closer to 100–500×). Cosmetically deployed across MW fractions: high-MW forms a discrete film on the surface that physically reduces TEWL and inhibits skin hyaluronidase (reducing breakdown of endogenous HA); lower-MW fractions humectant-hydrate in the stratum corneum. Distinct enough from HA to stack rather than substitute.
Clinical evidence · Emerging
Solid in-vitro and supplier-clinical data on humectancy, hyaluronidase inhibition, and TEWL reduction; independent dermatology RCTs are smaller and still maturing; the 'better than HA' claim rests largely on supplier comparisons.
Effective concentration range
0.1–2%
Formulation notes
Pairs powerfully with HA and ectoin in layered hydration systems (per Biossance Copper Peptide Rapid Plumping Serum trials: 100% noticed fine-line improvement at 4 weeks).
Watchouts
'PGA' also abbreviates poly-glycolic acid — confirm the INCI is polyglutamic acid, not an exfoliant.
Controversies & overclaims
The headline '5,000× weight in water' metric is a per-molecule chemistry-class figure that does not translate to in-use cosmetic performance — total skin hydration scales with formulation dose and supporting humectants, not single-molecule capacity. The 'PGA' abbreviation collides with poly-glycolic acid (an exfoliating acid) in some labelling contexts — INCI clarity matters.
Market positioning
Sold as the 'next-generation HA' — and the honest position is closer to 'excellent complement to HA in multi-humectant systems', not a replacement. The hyaluronidase-inhibition mechanism is the genuine differentiator and underused in marketing.
Comedogenicity
0 / 5
Sensitisation risk
Low
INCI & aliases
Polyglutamic Acid
Clean beauty perception
Strongly positive — fermentation-derived, biodegradable, non-comedogenic, animal-free.
Related ingredients
Graph relationships
Timeline