Mescaline: a survey.

The hallucinogen mescaline is found in the peyote and San Pedro cacti, which are prevalent in Mexico and the southwestern United States. In a survey of middle-class, predominantly white adolescents in a drug treatment facility, 18 percent of the respondents indicated that they had taken mescaline. Much of the purported mescaline was probably another hallucinogen, usually LSD. The effects of equipotent doses of mescaline and LSD are almost indistinguishable.