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Hydration & barrier

Polyglutamic acid

also known as PGA

A fermented humectant that holds many times more water than hyaluronic acid — and locks it in with a thin, breathable film.

What it actually does

Polyglutamic acid is a polymer of glutamic acid, typically produced by fermenting natto (the same bacterium behind Japanese fermented soybeans). It holds significantly more water than hyaluronic acid by weight and forms a thin film that slows transepidermal water loss — so it acts as both humectant and light occlusive in one ingredient. You'll see it stacked with hyaluronic acid in K-Beauty essences for a more layered hydration effect.

Who it's for

Dehydrated or tight skin, especially in dry climates where straight hyaluronic acid underperforms. Plays well with every skin type.

How to use it

Apply to damp skin and seal with moisturizer, exactly like you would a hyaluronic acid. Stacks fine with niacinamide, centella, peptides, and retinoids.

Products with polyglutamic acid

none tracked yet

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