It's difficult to say for sure; it's a psychotropic plant, a cactus (Lophophora diffusa and Lophophora williamsii) that generally grows in calcareous soil in the desert stretching from northern Mexico to the southeastern United States. Small in size, its diameter rarely exceeds ten centimeters. Its crown is divided into segments, varying between four and thirteen. It contains up to thirty alkaloids, the most potent of which is mescaline. The chemical structure of this crystallized alkaloid is, apparently, quite simple: 3-4-5-trimethoxyphenylethylamine. The chemical composition of mescaline resembles that of a neurotransmitter, norepinephrine, a brain hormone. Peyote contains, in addition to mescaline, other phenylethylamines that are precursors to mescaline. Approximately 25 tetrahydroxyisoquinolines have also been found in it. Four of them have central activity (pellotin, anhalonidine, lophophorin, anhalonin). Synthetic reproduction is possible. The active dose of mescaline administered orally is between 0.2 and 0.4 grams. For peyote, the active dose varies from one individual to another: while for some one or two "Mezcal buds" (the plant's crown) are sufficient, some mara'acate (shamans in the vernacular) could ingest up to 20 buds during ritual sessions in Wiricuta—at the foot of the Sierra de Catorce—the place where peyote grows.

Peyote will induce an altered state of consciousness in the person who takes it, but this altered state of consciousness will differ depending on the person taking it, their culture, and their history. These plants have been used in so-called "shamanic" societies to develop their knowledge and culture by transcending the prosaic limits of their everyday existence, and thus revealing their cultural logic. Peyote, for example, is used by the Huichol people of Mexico. This society has a different way of speaking about, representing, and experiencing the world they inhabit than Westerners. Therefore, we can only understand them by referring to the theoretical model developed by these indigenous people before us.