Polyglutamic Acid binds water at the surface and helps the formula feel cushioned.
Polyglutamic Acid is often compared with hyaluronic acid because both bind water. The difference is behaviour. PGA forms more of a surface film, which helps the product feel plush and helps hydration stay around longer.
That surface role is not a bad thing. Skin needs surface hydration too, especially in overnight formulas where the product is expected to sit comfortably for hours. PGA helps create that soft, hydrated finish without needing the formula to feel greasy.
In a multi-humectant formula, this is exactly the kind of ingredient that rounds things out. HA variants bind water in different ways. Polyglutamic Acid adds a film-forming hydration layer on top.
HA hydrates. PGA helps the hydration feel plush.
