Polyglutamic Acid

INCI: Polyglutamic Acid
Category: Humectant, Film-forming agent
Used in: Skincare -  serums, moisturisers, toners, masks
Typical Usage Level (Topical):
 0.1% – 3% in leave-on skincare formulations

What This Ingredient Does

Polyglutamic Acid (PGA) is a moisture-binding biopolymer produced through microbial fermentation. In skincare, it functions primarily as a humectant and film-forming ingredient that helps the skin retain hydration.

When applied topically, polyglutamic acid forms a lightweight, breathable film on the skin’s surface that helps reduce transepidermal water loss (TEWL). By slowing the evaporation of moisture from the skin, it allows hydration to remain within the outer layers of the skin for longer periods, helping improve softness, smoothness, and overall skin comfort.

Polyglutamic acid also works well alongside other humectants such as hyaluronic acid, glycerin, and beta glucan, helping extend the hydration they provide and supporting a more resilient skin barrier.

Key Benefits

• Helps reduce transepidermal water loss (TEWL)
• Improves skin hydration and moisture retention
• Enhances the performance of humectants such as hyaluronic acid and glycerin
• Supports smoother, softer and more supple skin
• Lightweight and suitable for daily use across skin types

Who It’s Best For

• Dehydrated or moisture-depleted skin
• Skin experiencing tightness or rough texture
• Mature skin with dehydration-related fine lines
• Sensitive or barrier-compromised skin
• All skin types including oily and combination skin

Clinical Note by Dr. Su

M.D. Dermatologist

Polyglutamic acid is a highly effective moisture-retention ingredient that helps the skin hold onto hydration for longer. When combined with humectants like hyaluronic acid and glycerin, it can contribute to more sustained hydration and improved skin barrier comfort.