PCA (pyroglutamic acid)

PCA (pyrrolidone carboxylic acid, also known as pyroglutamic acid) is a derivative of the amino acid glutamic acid. In the stratum corneum, it is one of the key components of the natural moisturizing factor (NMF), alongside amino acids, lactates and urea.

It works as a humectant: it attracts water and holds it in the epidermis, leaving skin soft, smooth and less prone to dryness. In cosmetics, it is usually combined with its sodium salt (Sodium PCA), amino acids and sodium lactate.

You'll find it in creams, serums, micellar waters, facial cleansing foams and foundations.