Product: Zinc is a metallic chemical element. Zinc PCA is the zinc salt of L-pyrrolidone carboxylic acid. It inhibits the enzyme 5-alpha reductase that catalyses the production of dihydroxy testosterone, a hormone that controls sebaceous gland activity. Zinc PCA is also a natural moisturizing factor (NMF) of the amino acid type. Zinc salts have a strong antibacterial activity.
There was no evidence of irritation, phototoxicity, sensitization, or comedogenicity found. Zinc PCA was found to be non-irritating and non-sensitising (with and without UV exposure). It was concluded that zinc PCA is safe as presently used in cosmetic formulations. This ingredient, however, should not be used in cosmetic products containing nitrosating agents.