Mescaline is a naturally occurring psychedelic phenethylamine found in peyote and San Pedro cacti, with stimulant and hallucinogenic effects and a history of ceremonial use

Mescaline is a naturally occurring psychedelic phenethylamine present in several cacti, especially peyote and San Pedro, and has long been used for its hallucinogenic and stimulant effects. Indigenous ceremonial use forms an important part of its historical and cultural context. Mescaline produces altered perception, changes in mood, and intensified sensory experience. Its significance spans pharmacology, ethnobotany, and the history of psychoactive substance use, linking plant-based traditions with modern understandings of psychedelics. Reference treatment of mescaline typically centers on its botanical sources, psychoactive properties, and longstanding ritual importance, making it a foundational substance in discussions of classic plant psychedelics.