Abstract Mescaline (CAS: 54-04-6) is a hallucinogen found in several North and South American cacti including Lophophora williamsii, which is often simply referred to as peyote. Mescaline is a ring-substituted amphetamine (3,4,5-trimethoxyphenethylamine) and a naturally occurring member of the phenethylamine class of intoxicants. In addition to being a drug of abuse, mescaline is most commonly used as a Native American religious intoxicant. Mescaline has no medical uses. Treatment of mescaline toxicity is symptomatic and generally requires supportive care only.