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 is
A polymer of glutamic acid produced by fermentation (the same bacterium responsible for natto). Larger and more water-binding than hyaluronic acid.
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.
Best for
- Dehydration
- Dry climates
Pairs well with
Routine placement
- Where it lives
- Essence · Serum · Moisturizer
- AM/PM
- AM & PM
- Frequency
- Daily
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.
The Plug verdict
The upgrade to hyaluronic acid nobody asked for but everyone benefits from once they try it.
Products featuring polyglutamic acid
2 productsEditorially picked products where polyglutamic acid is the hero — ranked by real value across authentic retailers.
Products with polyglutamic acid
none tracked yetWe're not surfacing any tracked products containing polyglutamic acid right now — we'll add them as our authentic retailers stock them.
We match by ingredient mentions in product copy from our authentic retailers. If we missed a product you know contains polyglutamic acid, let us know.
Related ingredients
Hyaluronic acid
aka Sodium hyaluronate
The water magnet — pulls moisture into the upper skin layers for instant plump.
Beginner-safe
Beta-glucan
An oat-derived humectant that hydrates deeper than hyaluronic acid and soothes at the same time.
Beginner-safe
Snail mucin
aka Snail secretion filtrate
Korea's cult hydrator — a glycoprotein-rich filtrate that plumps, soothes, and helps skin recover.
Beginner-safe
Frequently asked
- What does Polyglutamic acid do?
- A fermented humectant that holds many times more water than hyaluronic acid — and locks it in with a thin, breathable film.
- Is Polyglutamic acid good for beginners?
- Yes — Polyglutamic acid is considered beginner-friendly in most K-beauty routines.
- Is Polyglutamic acid safe for sensitive skin?
- Polyglutamic acid is generally well-tolerated on sensitive skin.
- How do you use Polyglutamic acid?
- Apply to damp skin and seal with moisturizer, exactly like you would a hyaluronic acid. Stacks fine with niacinamide, centella, peptides, and retinoids.