It is a constituent of the fruits of Ammi majus. Like other psoralens, trioxsalen causes photosensitization of the skin. It is administered topically or orally in conjunction with UV-A for phototherapy treatment of vitiligo and severe psoriasis. It has a role as a dermatologic drug, an antineoplastic agent, a photosensitizing agent, a cross-linking reagent and a plant metabolite. It is a member of psoralens and an aromatic ether. It is functionally related to a psoralen.