Mescaline, the psychoactive alkaloid found in the peyote cactus (Lophophora williamsii) and several other cactus species, takes its name from the Nahuatl word mexcalli, transmitted through Spanish mezcal. The Nahuatl compound combines metl (agave) and ixcalli (cooked or baked), originally referring to the cooked heart of the agave plant. The application of this term to the peyote cactus reflects the colonial-era confusion or conflation between different plants used by indigenous Mesoamerican peoples.
Mescaline holds a unique place in the history of psychopharmacology: it was the first psychedelic compound to be isolated and chemically identified. In 1897, the German chemist Arthur Heffter extracted the pure alkaloid from peyote buttons and tested it on himself, documenting its hallucinogenic effects with scientific rigor. The compound was subsequently synthesized in the laboratory by Ernst Späth in 1919, making mescaline the first psychedelic available in pure, measured doses.
The indigenous use of peyote — and therefore mescaline — extends back millennia. Archaeological evidence from caves in the Rio Grande region suggests peyote use dating to at least 3700 BCE. The Huichol, Tarahumara, and other indigenous peoples of Mexico have used peyote in religious ceremonies for centuries, and the Native American Church, founded in the late 19th century, incorporated peyote ritual into a syncretic Christian-indigenous framework.
Mescaline gained literary fame through Aldous Huxley's 1954 essay The Doors of Perception, which described his experiences with the drug in precise, philosophical prose. Huxley argued that mescaline temporarily removed the brain's filtering mechanisms, allowing direct perception of reality as it truly is. The title, drawn from William Blake, later inspired Jim Morrison to name his band The Doors — making a Nahuatl word, via chemistry, via literature, a foundation of rock music history.
Chemically, mescaline is a phenethylamine — structurally related to dopamine and adrenaline. Its hallucinogenic effects arise from interaction with serotonin receptors, particularly 5-HT2A. Unlike many other psychedelics, mescaline occurs naturally in several cactus species besides peyote, including the San Pedro cactus (Echinopsis pachanoi) of South America, which has its own independent tradition of ritual use in Andean cultures.