Psilocybin mushrooms, also known as psychedelic mushrooms, are mushrooms that contain the psychedelic compounds psilocybin and psilocin.nspired by the Wassons' Life article, Timothy Leary traveled to Mexico to experience psilocybin mushrooms firsthand. Upon returning to Harvard in 1960, he and Richard Alpert started the Harvard Psilocybin Project, promoting psychological and religious study of psilocybin and other psychedelic drugs.