What is Polyglutamic Acid? – Skin Rocks

What is Polyglutamic Acid?

What is it?

Originally used in medicine for its wound-healing abilities, Polyglutamic Acid (PGA) is a humectant (attracts and retains water in the skin) and is touted for its ability to hold more moisture than popular fellow hydrator, Hyaluronic Acid.

Formed when multiple glutamic acid molecules link together (hence the name polyglutamic acid), PGA is an amino acid that's produced during the fermentation of soybeans.

We asked Skin Rocks Biochemist, Ashley for her thoughts. Here's what she said: 

“Polyglutamic acid (PGA) works similarly to hyaluronic acid (HA), BUT there's a key difference. Both ingredients are humectants which mean they hydrate the skin by attracting water. This is different to a traditional moisturiser whose primary function is to support the skin's barrier. PGA has a higher molecular weight than hyaluronic acid which means its mode of action is surface hydration and forms a film over the skin's surface.

It also helps promote the production of natural HA and is said to lock-in 4x the amount of water than HA.  However, it's not a direct substitute for HA, which works to hydrate the skin at a deeper level. If you are looking to hydrate, I’d recommend either PGA or HA followed by a moisturiser. For those looking for a stronger approach to hydration, use the two in combination.”


Hydrates – Its main purpose within skincare is to act as a humectant. Drawing water to the upper layers of the skin from the environment or deeper within the skin and creating a film to prevent it from evaporating. 

It's also been found to stimulate the production of natural moisturising factors (NMF) on the surface of your skin which is great news for those with sensitised skin as the NMF are responsible for keeping your skin supple and hydrated. 

Improves skin elasticity and suppleness – Research has shown that PGA can inhibit an enzyme called hyaluronidase, which breaks down hyaluronic acid, a naturally-occurring humectant that helps your skin retain moisture. Hyaluronic acid depletes as we age, so PGA may be particularly beneficial for those concerned about the signs of ageing.  

Plumps fine lines and wrinkles – Polyglutamic acid's ability to help smooth fine lines is twofold. It increases hydration levels in your skin, which mitigates fine lines that appear in response to dehydration. It also helps prevent the depletion of hyaluronic acid, which is proven to stimulate collagen and elastin – the proteins responsible for giving your skin its elasticity and smooth appearance.

Who is it for?

- Dehydrated skin 

- Dry skin

Polyglutamic acid is safe for all skin types, however, for those with particularly sensitive skin, we recommend patch testing before adding it to your routine.