Definition

A tryptamine alkaloid, isolated from various genera of fungi including the genus Psilocybe, with hallucinogenic, anxiolytic, and psychoactive activities. In vivo, psilocybine is rapidly dephosphorylated into the active compound psilocin, which activates serotonin 2A (5-HT2A) receptors in the central nervous system (CNS), mimicking the effects of serotonin.