Bufotenin is a chemical constituent in the secretions and eggs of several species of toads belonging to the genus Bufo, but the Colorado River toad (Incillius alvarius) is the only toad species in which bufotenin is present in large enough quantities for a psychoactive effect. Extracts of toad secretion, containing bufotenin and other bioactive compounds, have been used in some traditional medicines such as ch’an su (probably derived from Bufo gargarizans), which has been used medicinally for centuries in China.[1]