Peyote vs San Pedro: Botanical and Cultural Distinctions

Urgent first. For suspected poisoning or a medical emergency, call 911 or US Poison Help at 1-800-222-1222. In the US, call or text 988 for a mental health crisis.

This page is education only. It gives no identification keys, no harvesting, growing, preparation or use information. Peyote is also sacred to many people, so we describe it respectfully and only as the sources do.

Two different plants

Both cacti contain mescaline, but they are not the same plant, and "cactus" tells you very little.

Naming caution: sources use different names for San Pedro. One scholarly paper uses Echinopsis, another uses Trichocereus, and taxonomy databases may revise names again. [5][4][2] Check the source's own name before comparing studies. Neither name tells you anything about safety.

Mescaline content: what can and cannot be said

Mescaline is highly concentrated in only a few cactus species, notably peyote and the South American wachuma (T. pachanoi, T. peruvianus, T. bridgesii). [4] A study of 14 taxa and cultivars of the Echinopsis subgenus Trichocereus found mescaline in all, with results spanning two orders of magnitude, from 0.053% to 4.7% by dry weight of stem tissue, measured by one laboratory method. [5] Those are measurements of specific cultivated plants and do not give a "typical" figure for San Pedro or for peyote. Do not compare them with another study's method.

Cultural contexts

• Peyote. Archaeological evidence of peyote use dates back more than 5,000 years in Mesoamerica. [6] Native American Church use is a specific religious practice. The Native American Church of North America commissioned a Peyote Research Project, which found the plant was threatened in both its populations and its quality. [7] The MAPS bulletin advises not using it outside a bona fide Native American Church context. [7] In the US, peyote is described as growing naturally only in Texas, where development, habitat loss and over-harvesting are cited as pressures. [8]
• San Pedro. Archaeological studies in Peru, the United States and Mexico suggest mescaline-containing cacti in general have been used for more than 6,000 years, so this is not specific to San Pedro. [4] A chemical study linked the highest mescaline content, particularly E. pachanoi from Peru, to documented shamanic use. [5]

We do not describe ceremonies. For the peoples and context see peyote and its traditional contexts and mescaline-cactus traditional contexts. Peyote's conservation is on peyote conservation.

Risks and evidence

Evidence labels: insufficient evidence for clinical benefit of either cactus; Proper evidence not found for a head-to-head human comparison (we checked PubMed).

A toxicology review of peyote and mescaline reported most intoxications as mild and addiction practically absent, but noted most reports lacked confirmation of exposure. [9] A controlled trial in healthy adults exists, but it tested mescaline as a drug, not a cactus. [10] Cactus plants contain other substances and variable amounts.

Legal status

Not legal advice; laws change. In the United States, 21 CFR 1308.11 lists mescaline and the peyote plant (Lophophora williamsii) in Schedule I. [11] A separate regulation says the peyote listing does not apply to nondrug use of peyote in bona fide religious ceremonies of the Native American Church. [12] We did not find San Pedro cacti named in the text of the 1308.11 section, but that does not tell you whether possession or any other activity is lawful, and mescaline itself is listed. Other countries: not verified. See psychedelic legal status by country.

Related guides

Plant profiles: peyote, San Pedro cactus. Compound: mescaline.