Manganese PCA is the manganese salt of pyrrolidonecarboxylic acid (PCA means "pyrrolidonecarboxylic acid" manganeseese "manganese") with the empirical formula C5H7NO3Mn. The substance is used in cosmetic formulations. It acts as a moisturizer (increases the water content of the skin) and humectant (preserves the moisture of the skin). It also has a skin-caring effect.