What is it?
Polyglutamic acid (PGA) is a powerful humectant derived from fermented soybeans. It’s a naturally occurring peptide made up of glutamic acid units and is most well known for its impressive water-binding abilities. While it’s newer to the skincare scene than hyaluronic acid, it’s gaining popularity for its ability to deeply hydrate and improve skin texture.
How it works in skincare
Polyglutamic acid works by attracting and holding onto moisture, helping the skin retain water and stay hydrated for longer. It forms a breathable, protective film on the skin’s surface, which not only helps prevent water loss (also known as transepidermal water loss or TEWL) but also enhances the skin’s natural barrier function. Some research suggests PGA can hold up to four times more moisture than hyaluronic acid, making it an especially effective ingredient for boosting hydration.
In addition to its hydrating properties, polyglutamic acid can help improve skin elasticity, smooth the appearance of fine lines, and leave the skin feeling soft and plump. It’s suitable for most skin types, including sensitive skin, and works well in both standalone hydrating serums and multi-ingredient formulas.
PGA is often layered alongside other moisturising ingredients like hyaluronic acid, glycerin, and ceramides. It sits well under sunscreen and makeup, and because it works mainly at the surface level, it complements ingredients that penetrate deeper into the skin. Its film-forming ability may also help other actives stay on the skin longer, potentially increasing their effectiveness.
How to use it
To use polyglutamic acid effectively, apply it to slightly damp skin after cleansing and before moisturiser. It can be used daily, morning or night, and generally plays well with most other ingredients. Those with dry, dehydrated, or compromised skin barriers may notice particular benefits from regular use.
