Mescaline is a psychoactive phenethylamine from peyote and other cacti, associated with Indigenous ritual use, altered perception, and the history of psychedelic research

Mescaline is a naturally occurring psychedelic phenethylamine found in peyote and some other cacti, long associated with Indigenous ceremonial use in the Americas and with early scientific interest in altered states. Its effects typically include visual changes, shifts in mood and thought, and altered sensory perception, making it one of the best known classic psychedelics. Mescaline also occupies an important place in the history of psychiatry, psychopharmacology, and modern drug culture. Interest in the substance connects ethnobotanical traditions with laboratory research, debates over consciousness, and the development of later psychedelic science. Its significance extends beyond pharmacology because peyote use is tied to religion, cultural continuity, and legal protections for some Indigenous communities. That combination of ritual context, historical influence, and psychoactive effects makes mescaline a recurring reference point in discussions of psychedelics.