Polyglutamic acid (PGA) is a water-soluble peptide derived from fermented soybeans. It consists of multiple glutamic acid molecules linked together, which gives it an exceptional ability to retain moisture. PGA is known to hold up to 5,000 times its weight in water, making it even more hydrating than hyaluronic acid. enhances skin hydration by forming a protective film on the surface of the skin, preventing moisture loss and improving overall skin elasticity. Here are 5 amazing benefits of using skincare ingredient.