Polyglutamic acid

Polyglutamic acid (PGA) is a humectant produced by fermentation, often from the bacterium behind natto (fermented soybeans). It is a large molecule that forms a moisture-holding film on the skin surface, and it is frequently promoted as holding even more water than hyaluronic acid, giving it a role in the glass-skin hydration trend. The evidence is moderate. PGA is documented as an effective surface humectant that boosts hydration and skin smoothness, and there is some suggestion it may help inhibit hyaluronidase (an enzyme that breaks down the skin's own hyaluronic acid), which could support moisture retention. Its benefits are real but sit at the surface; it is a hydration-and-finish ingredient rather than a deep-acting active. It is best for people wanting a plump, dewy, smooth finish and lasting surface hydration, across most skin types including dehydrated and dull skin. It maps to dehydration and dullness concerns. Layering is easy and complementary. PGA pairs especially well with hyaluronic acid (surface plus deeper hydration) and with niacinamide, panthenol and glycerin, and it makes a nice final hydrating layer before moisturizer. There are no notable conflicts, and sealing it with a cream helps in dry climates. On safety, polyglutamic acid is very well tolerated, typically fragrance-free, and low in irritation potential. It does not feed Malassezia, so it suits fungal-acne-prone routines. No specific pregnancy concerns are documented for topical PGA, and its gentle profile makes it a low-risk choice, though as with any product, confirm with your clinician if you have specific concerns during pregnancy or breastfeeding.