分子式：C5H7NO3 分子量：129.11 Cas No：98-79-3; 149-87-1
吡咯烷酮羧酸是存於皮膚角質層的自然保濕成份NMF (Natural Moisturizing factor )當中保濕性最強的。
PCA stands for Pyrrolidone Carboxylic Acid and though it might not sound like it, it is a thing that can be found naturally in our skin. In fact, after amino acids, it is the second biggest NMF component of the skin with 12% being PCA of the NMF composition of normal skin. So similar to other NMFs, it's a skin goodie that helps the skin to hold onto water and stay nicely hydrated.