Phenylalanine
Phenylalanine is an essential amino acid that the human body cannot synthesize on its own and must obtain through diet. It is classified as a skin-identical ingredient, meaning it is naturally present in the skin. In cosmetic formulations it appears in a range of moisturizers, cleansers, and serums. When combined with UVA exposure, it has been investigated for the treatment of vitiligo, a pigmentation disorder characterized by loss of skin pigment in patches.
Phenylalanine is used as a skin-identical ingredient that mirrors components naturally found in skin. In combination with UVA irradiation, it has been studied as a treatment for vitiligo to help restore pigmentation in affected areas.
When used in vitiligo treatment protocols, phenylalanine is combined with UVA exposure, which carries inherent photosensitivity and UV-related risks. Standard cosmetic use cautions are not explicitly noted in the source.
