Mescaline is a naturally-occurring classical psychedelic substance of the phenethylamine class. It occurs naturally in the peyote cactus (Lophophora williamsii), San Pedro cactus (Echinopsis pachanoi), Peruvian Torch cactus (Echinopsis peruviana), as well as the Cactaceae plant and the Fabaceae bean families. It is one of the oldest known hallucinogens and the parent compound of the psychedelic phenethylamines, one of the two major subclasses of psychedelic compounds (along with tryptamines).

Peyote, San Pedro, Cactus, Buttons, 3,4,5-Trimethoxyphenethylamine

Subjective effects include open and closed-eye visuals, time distortion, enhanced introspection, conceptual thinking, euphoria, and ego loss. Mescaline is generally considered to be one of the most gentle, insightful, and euphoric psychedelics. It is known for placing greater emphasis on bodily and tactile sensations (sometimes compared to MDMA) than psychedelic tryptamines, like psilocybin or DMT, which tend to have a more frenetic headspace and dynamic visual geometry.

The ritual use of the Peyote cactus has occurred for at least 5700 years by Native Americans in Mexico. Other mescaline-containing cacti, such as the San Pedro, have a long history of use in the South American continent, from Peru to Ecuador. Mescaline was first isolated and identified in 1897 by the German chemist Arthur Heffter, and first synthesized in 1919 by Ernst Späth. It was one of the first psychedelics to be experimented with by Western intellectuals like Aldous Huxley, who famously described its effects in the 1954 essay “The Doors of Perception.” Mescaline is an important part of American chemist Alexander Shulgin’s work, who used it as a starting point for synthesizing dozens of novel psychedelic compounds that are documented in his 1991 book, PiHKAL.