Natural Psychedelics · Cactus and sacrament with no approved medical use
Peyote
Lophophora williamsii · also called Peyote buttons (the dried tops); the cactus behind mescaline
Peyote is a small, spineless cactus from southwest Texas and Mexico. It is a sacrament for the Native American Church and other Indigenous peoples. Its best-known chemical is mescaline, a strong psychedelic. Almost all modern controlled research uses pure mescaline in healthy volunteers, not the cactus. The most important cautions are the strong, long-lasting effects, mental health and heart risks, and that the plant is threatened and sacred.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Peyote
Peyote (Lophophora williamsii) is a cactus and a sacrament for the Native American Church and other Indigenous peoples. It has no approved medical use. Controlled human research uses pure mescaline in healthy volunteers. The plant is declining in Texas and is a legally protected religious sacrament in the United States.
What peyote is
Peyote is the common name of Lophophora williamsii, a small, spineless cactus of the cactus family. GBIF accepts the name. It grows naturally in southwest Texas and northern and central Mexico.
Its dried tops are called buttons. The best-known chemical in the cactus is mescaline. More than 40 alkaloids have been isolated from the genus, but only mescaline has been studied much.
There is one other recognised species, Lophophora diffusa. Its main alkaloid is pellotine, not mescaline. One lab study found peyote plants with no mescaline, so a plant's name does not tell you what it contains.
Tradition and respect
For many Indigenous peoples of North America, peyote is a sacrament. The Native American Church uses it in prayer ceremonies, and members describe it as sacred. This page does not describe ceremonies and does not treat tradition as clinical evidence.
Two peyote buttons from a Texas museum were dated to around 3780 to 3660 BC and contained mescaline. The authors say this supports the idea that native North Americans knew the plant's effects as long as 5,700 years ago.
Native American Church writers ask outsiders to respect Indigenous sovereignty over the medicine. A 2026 commentary argues that research must include free, prior and informed consent, benefit-sharing and Indigenous leadership.
Conservation
Peyote is slow to recover. In Texas, a 2025 news report said supply is declining because of development and habitat loss, over-harvesting and poaching, and that only four active licences to harvest and distribute peyote were reported.
The Indigenous Peyote Conservation Initiative, formed in 2017 by the National Council of Native American Churches, says peyote is threatened in numbers and quality and asks outsiders to support Native-led conservation.
Secondary summaries report the plant as Vulnerable on the IUCN Red List and cacti as listed in CITES Appendix II. We could not read the IUCN or CITES pages ourselves, so treat those two listings as unconfirmed.
What the research shows
There is no modern randomised trial of peyote itself in any illness. Almost all controlled work uses pure mescaline in healthy volunteers, and shows how it acts, not that it helps.
One observational study found no memory or mental health deficits in Navajo Native American Church members who took peyote regularly. Surveys report improved well-being, but cannot show cause.
A 2026 clinician primer says controlled trials in patients are lacking, so safety and benefit in people with illness are unclear.
Legal status as regulators state it
Not legal advice; laws differ by country and change. In the United States, peyote and mescaline are in Schedule I (21 CFR 1308.11, read 2026-10-25).
A separate federal rule (21 CFR 1307.31) says the listing does not apply to nondrug use of peyote in bona fide religious ceremonies of the Native American Church. A federal law (42 U.S.C. 1996a) states that use by a member of an Indian tribe for bona fide traditional ceremonial purposes in a traditional Indian religion is lawful and shall not be prohibited by the United States or any State.
These are exemptions for a specific religious community, not general permission. Rules in Mexico, Canada, Europe and elsewhere were not checked here.
At a glance
Traditional uses history, not proof
- Used as a sacrament in Native American Church prayer ceremonies (news report, review).
- Archaeological peyote buttons from Texas date to about 3780 to 3660 BC (El-Seedi and colleagues).
- Described by Native American Church members as sacred, "God in plant form" (Texas Public Radio).
Studied for research
- Thinking and mental health in long-term ceremonial users, low
- Alcohol use, insufficient (no controlled trial)
- Mood and well-being, very low (surveys)
- Pure mescaline effects in healthy volunteers, moderate (not a benefit)
Main compounds
- Mescaline, the best-known alkaloid
- More than 40 other alkaloids in the genus, poorly studied
- Pellotine is the main alkaloid in the related L. diffusa
Common forms
Research links: 21 CFR 1308.11 (US Schedule I) · 21 CFR 1307.31 (Native American Church) · 42 U.S.C. 1996a · Navajo peyote users study (abstract) · Mescaline volunteer trial (abstract) · Peyote and mescaline review (abstract) · Research Library · Genes & Biomarkers Library
The plant and its history
- Accepted scientific name
- Lophophora williamsii
- Naming authority
- (Lem. ex Salm-Dyck) J.M.Coult.
- Common names
- Peyote (English)
- Botanical family
- Cactaceae (the cactus family)
- Classification
- Plantae > Cactaceae > Lophophora > Lophophora williamsii
- Native range
- Southwest Texas (USA) and northern and central Mexico (Chihuahua, Coahuila, Durango, Jalisco, Nuevo Leon, San Luis Potosi, Tamaulipas, Zacatecas), per GBIF distribution records from the Catalogue of Life.
- Habitat
- Not checked in the sources read.
- What the plant looks like
- Roots: Not described in the sources read.; Stems: A small, spineless cactus; the dried tops are called buttons (El-Seedi and colleagues).; Leaves: None (cactus).; Flowers: Not checked.; Fruit: Not checked.
- Cultivation
- Not covered.
- Harvest and processing
- Not covered.
- Look-alikes and adulterants
- Name: Lophophora diffusa ("false peyote"); Note: The only other recognised species in the genus. Its major alkaloid is pellotine, not mescaline. Several unrelated cacti are also called "false peyote". No identification guidance is given here.
- Sustainability and conservation
- See the Safety tab. Reported as Vulnerable (IUCN) and in CITES Appendix II from secondary sources; not verified from primary pages. Supply in Texas reported as declining.
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| Archaeological record, Texas and Mexico | Two peyote buttons from a museum collection, presumably from Shumla Cave No. 5 on the Rio Grande, were radiocarbon dated to roughly 3780 to 3660 BC and contained mescaline. The authors say native North Americans recognised the plant's psychotropic properties as long as 5,700 years ago. | p15990261 |
| Native American Church (United States) | The Native American Church uses peyote as a sacrament in prayer ceremonies. Members describe peyote as sacred. This page does not describe ceremonies. | s-tpr-2025 |
| Navajo healing | Among the Navajo, the Native American Church and Pentecostal Christianity have been more active than traditional Navajo healing in responding to alcohol and substance abuse. | p11224979 |
| Western science | Reviews say mescaline research has been limited since the early 1970s, after prohibition of psychoactive substances. | p36252614 |
| Other Indigenous peoples (for example the Huichol/Wixarika of Mexico) | Mentioned in sources as peoples with long peyote traditions, but not described from a source read here. NOT verified. | p38138432 |
Traditional use shows how a plant was used. It does not show that a supplement works or is safe today.
What is inside, and how it may work
What the plant contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Mescaline PubChem 4076 | phenethylamine alkaloid | Cactus top Varies. Some specimens held none in one lab study. | Serotonin 5-HT2A/2C agonist; also acts at some adrenergic and dopamine receptors. 32 22 13 | Human data |
| Other Lophophora alkaloids (pellotine, anhalonidine, hordenine and many more) | tetrahydroisoquinolines and others | Cactus top More than 40 alkaloids isolated from the genus. | Poorly studied; pellotine was briefly marketed around 1900 as a sleeping aid. 5 7 | Review |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| 5-HT2A serotonin receptor | HTR2A | In healthy volunteers, adding a 5-HT2A blocker weakened and shortened the effects of pure mescaline, which fits the receptor being the main route. 13 | Human data |
| Other receptors | adrenergic alpha-1A/2A, dopamine D1/2/3, 5-HT2C | Reported in a review as secondary actions; mostly lab or animal evidence. 22 | Review (lab/animal) |
| Isolated heart tissue | n/a | Mescaline alone did not increase force of contraction in mouse or human atrial tissue in a dish. 17 | Lab |
Absorption, metabolism and elimination
- Absorption
- By mouth; peak blood level at about 2 hours in volunteers given pure mescaline.
- Distribution
- Not read.
- Metabolism
- Mainly broken down to 3,4,5-trimethoxyphenylacetic acid (about 31% of the dose recovered in urine as this product in one analysis).
- Elimination
- Half-life about 3.5 hours; about 53% of the dose recovered unchanged in urine over 24 to 30 hours.
- Bioavailability
- At least about 53% by mouth, according to the authors' modelling.
Isolated compounds versus whole extracts
Nearly all controlled human data are for pure mescaline in healthy volunteers. Peyote cactus contains many other alkaloids, and ceremonial use takes place in a spiritual and social setting. Results from one cannot be assumed for the other.
Nutritional composition
Peyote is not a food or nutrient.
1 moderate certainty2 low certainty1 very low certainty1 not enough evidence
What is Peyote good for?
The uses people ask about and how strong the human evidence is. None is proven for peyote itself, and several rows describe pure mescaline, not the cactus.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Thinking, memory and mental health in long-term ceremonial users
Low certaintyOne comparison of Navajo Native American Church members found no memory, attention or mental health deficits linked to regular ceremonial peyote use.
1 studiesAmounts and preparations are not covered on this page.
Studies, doses and limits
What the trials found
One cross-sectional study compared 61 Native American Church members who regularly took peyote, 36 sober former drinkers and 79 Navajo adults with minimal substance use.
Results
The peyote group showed no significant deficits on the Rand Mental Health Inventory or ten neuropsychological tests, compared with the minimal-use group. The former-alcohol group did show deficits. Lifetime peyote use was not linked to performance.
Effect sizes as reported
No significant difference from the minimal-use group.
Why this rating
One observational study of 176 people, no randomisation. The authors warn it may not apply to illicit hallucinogen users.
Form and dose studied
Amounts and preparations are not covered on this page.
Who was studied
Navajo adults aged 18 to 45 who used peyote regularly in a religious setting.
Limits
People who stay in a religious tradition may differ from those who stop. Not a trial. One tribe, one time point.
Why researchers looked
Researchers asked whether regular ceremonial peyote use harms thinking or mental health, a question raised by the use of other hallucinogens.
Traditional use
For many Indigenous peoples of North America, peyote is a sacrament. The Native American Church uses it in prayer ceremonies. This page does not describe ceremonies. Traditional use is not clinical evidence.
Proposed mechanism Human pharmacology
Mescaline, the best-known alkaloid in peyote, switches on the serotonin 5-HT2A receptor, as other classic psychedelics do. In a human trial, a 5-HT2A blocker weakened and shortened its effects. Peyote holds many other alkaloids whose effects are poorly studied.
A proposed mechanism does not show that the effect happens in people.
This shows no detected harm to thinking in this group. It does not show peyote is safe for everyone, or for people with mental health or heart conditions.
Alcohol and substance use in a Native American Church setting
Not enough evidenceSome Native American Church members and writers describe peyote ceremonies as helping people leave alcohol. The scientific evidence is old, case-based and very weak.
3 studiesAmounts and preparations are not covered on this page.
Studies, doses and limits
What the trials found
No controlled trial of peyote for alcohol use disorder was found. A 1977 paper gave case histories; a 2000 anthropological article described the healing context; a 2026 systematic review of mescaline reports mentions improvements in alcohol use but calls the literature limited and variable.
Results
The 1977 case histories described abstinence under Indian guidance together with taking part in the ritual. The 2026 systematic review found only 10 suitable studies and drew no firm conclusions.
Effect sizes as reported
Not measurable from the sources read.
Why this rating
Case histories, anthropology and a thin systematic review. No controlled data.
Form and dose studied
Amounts and preparations are not covered on this page.
Who was studied
Native American Church members and other adults in case histories.
Limits
Peyote cannot be separated from the community, prayer and social support around it. No control groups.
Why researchers looked
Alcohol misuse has been a serious problem in many Native communities, and Native American Church healing has been described as one response.
Traditional use
Native American Church and Pentecostal Christianity are more active in treating alcohol and substance abuse among the Navajo than traditional Navajo healing is, according to one anthropologist.
Proposed mechanism Theory
A 1977 paper speculated about a chemical link between peyote alkaloids and alcohol dependence. This has not been tested in modern trials.
A proposed mechanism does not show that the effect happens in people.
Peyote is not a treatment for alcohol use disorder. Anyone struggling with alcohol should talk to a doctor.
Mood and well-being
Very low certaintyPeople who report using peyote or San Pedro for spiritual reasons often report feeling better afterwards. Surveys cannot show peyote caused this.
3 studiesAmounts and preparations are not covered on this page.
Studies, doses and limits
What the trials found
An online survey of 452 mescaline users, plus a 2026 systematic review that found only 10 suitable studies. No modern randomised trial of peyote or mescaline in people with depression or anxiety was found.
Results
In the survey, about half reported a psychiatric condition and most of those (over 67%) reported improvement after their most memorable experience. In the systematic review, studies reported improvements in depression scales and well-being, but the authors said quality was too variable for firm conclusions.
Effect sizes as reported
Not available.
Why this rating
Self-reports and low-quality studies, no controls, and people who choose to use are not a random group.
Form and dose studied
Amounts and preparations are not covered on this page.
Who was studied
English-speaking adults who had used mescaline (mostly peyote or San Pedro), mostly infrequently.
Limits
Online self-selected sample; improvement may reflect expectation, setting or other changes.
Why researchers looked
Interest in mescaline as a possible medicine has grown, but modern trials in patients are missing.
Traditional use
For many Indigenous peoples of North America, peyote is a sacrament. The Native American Church uses it in prayer ceremonies. This page does not describe ceremonies. Traditional use is not clinical evidence.
Proposed mechanism Human pharmacology
Mescaline, the best-known alkaloid in peyote, switches on the serotonin 5-HT2A receptor, as other classic psychedelics do. In a human trial, a 5-HT2A blocker weakened and shortened its effects. Peyote holds many other alkaloids whose effects are poorly studied.
A proposed mechanism does not show that the effect happens in people.
Mescaline can also cause fear, confusion and psychosis-like effects. See the Safety tab.
Acute effects of purified mescaline in healthy volunteers
Moderate certaintyIn careful lab trials, purified mescaline produces a long-lasting psychedelic state, similar to LSD or psilocybin. This tells us how it acts, not that it treats anything.
4 studiesAmounts and preparations are not covered on this page.
Studies, doses and limits
What the trials found
Two randomised, double-blind, placebo-controlled crossover trials in healthy volunteers (16 and 32 people), plus a pooled analysis of 49 participants. The substance was pure mescaline, not peyote.
Results
Effects rose with dose and lasted about 6 to 14 hours depending on dose; mean about 11 hours at a high-moderate dose. At equally strong doses the experience was comparable to LSD and psilocybin. Nausea and vomiting were frequent at the highest dose. A 5-HT2A blocker reduced the effects.
Effect sizes as reported
Not applicable (descriptive pharmacology).
Why this rating
Randomised, blinded, placebo-controlled, but small and in healthy volunteers in a lab. Not a test of benefit.
Form and dose studied
Amounts and preparations are not covered on this page.
Who was studied
Healthy adults.
Limits
Purified compound, not the cactus; small groups; short follow-up; no patients.
Why researchers looked
Modern data on how mescaline acts in people were missing, so Swiss researchers tested it in healthy volunteers.
Traditional use
None.
Proposed mechanism Human pharmacology
Mescaline, the best-known alkaloid in peyote, switches on the serotonin 5-HT2A receptor, as other classic psychedelics do. In a human trial, a 5-HT2A blocker weakened and shortened its effects. Peyote holds many other alkaloids whose effects are poorly studied.
A proposed mechanism does not show that the effect happens in people.
This is not evidence of a medical benefit. Effects are long and strong.
Blood pressure and heart rate effects
Low certaintyPurified mescaline raised blood pressure and heart rate in healthy volunteers. This is a safety-related effect, not a benefit.
3 studiesAmounts and preparations are not covered on this page.
Studies, doses and limits
What the trials found
Healthy-volunteer trial of pure mescaline, plus a lab study on isolated human heart tissue.
Results
Systolic and diastolic blood pressure rose at doses above the lowest tested, with no difference between the middle and top doses; heart rate rose with dose. Isolated mouse and human atrial tissue did not show increased force with mescaline alone.
Effect sizes as reported
Not applicable.
Why this rating
One small trial in healthy volunteers plus a lab-dish study that does not reflect a living person.
Form and dose studied
Amounts and preparations are not covered on this page.
Who was studied
Healthy adults.
Limits
No data in people with heart disease. Lab-dish findings may not transfer.
Why researchers looked
Mescaline has a stimulant-like (sympathomimetic) side, so heart effects matter.
Traditional use
None.
Proposed mechanism Mixed lab and human
Mescaline is a phenethylamine, so a stimulant-like pattern is expected; isolated heart tissue did not respond to mescaline alone.
A proposed mechanism does not show that the effect happens in people.
People with heart disease or high blood pressure should talk to a doctor; data in them are lacking.
Connections to the rest of health
How Peyote connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Nervous System | Biological association | Low certainty | Studied for: Thinking, memory and mental health in long-term ceremonial users Studied for: Alcohol and substance use in a Native American Church setting | 12 3 10 19 21 20 13 14 16 22 |
| Cardiovascular System | Biological association | Low certainty | Studied for: Blood pressure and heart rate effects | 13 17 23 |
C. Body parts and organs
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Heart and blood pressure | Adverse effect or risk | Low certainty | Raised blood pressure and heart rate in one small trial; no data in heart disease. Preparation or compound: Purified mescaline in healthy volunteers |
13 |
E. Health conditions
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Memory, attention and executive-function test scores | Biological association | Low certainty | Measured in trials: no change. A lab change is not the same as a health benefit. | 12 |
| Rand Mental Health Inventory score | Biological association | Low certainty | Measured in trials: no change. A lab change is not the same as a health benefit. | 12 |
| Blood pressure | Biological association | Low certainty | Measured in trials: raised. A lab change is not the same as a health benefit. | 13 |
| Heart rate | Biological association | Low certainty | Measured in trials: raised. A lab change is not the same as a health benefit. | 13 |
J. Genes, receptors and enzymes
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| HTR2A (serotonin 5-HT2A receptor) | Preliminary mechanism | Human | Main target of mescaline. | 13 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Mescaline | Biological association | Human | Serotonin 5-HT2A/2C agonist; also acts at some adrenergic and dopamine receptors. Preparation or compound: Cactus top |
32 22 13 |
| Other Lophophora alkaloids (pellotine, anhalonidine, hordenine and many more) | Biological association | Review | Poorly studied; pellotine was briefly marketed around 1900 as a sleeping aid. Preparation or compound: Cactus top |
5 7 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 25, 2026).
Evidence at a glance: what changed in 2 lab markers
Tap a number to show only those markers. Counts are markers, not people.
The evidence
The research centre for Peyote. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We searched PubMed and read the abstracts of 22 papers, read US federal rules and statute text for the legal entries, and checked the plant name in GBIF and mescaline in PubChem. IUCN, CITES, Kew POWO and UN/INCB pages could not be read, so those entries are marked unconfirmed. Certainty ratings are the compiler's own reading.
Study library: every study we checked 33
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Albert 2026 Psychedelic exposure in pregnancy: a scoping review to inform perinatal drug safety and clinical counseling. Therapeutic Advances in Drug Safety · PMID 41930230 · DOI |
Scoping review |
23 23 primary human sources 1968-2020 (1 on mescaline/peyote) |
MDMA, LSD, mescaline/peyote and others in pregnancy n/a n/a n/a · vs n/a |
Only one eligible primary human study involved mescaline or peyote. The authors say human evidence is sparse and that absence of data should not be read as evidence of safety. Methods, limits and fundingOutcomes: Pregnancy and child outcomes Limitations: Sparse, small, confounded reports. Funding and conflicts: See paper. Read: abstract |
| Aragane 2011 Peyote identification on the basis of differences in morphology, mescaline content, and trnL/trnF sequence between Lophophora williamsii and L. diffusa. Journal of Natural Medicine · PMID 20890669 · DOI |
Lab analysis lab |
Lophophora specimens | Plant specimens n/a n/a n/a · vs n/a |
The genus has two species, L. williamsii (peyote) and L. diffusa. The authors found L. williamsii specimens that contained no mescaline, so mescaline content could not separate the species. Methods, limits and fundingOutcomes: Morphology, mescaline content, DNA Limitations: Small specimen set; a forensic-identification study. Funding and conflicts: See paper. Read: abstract |
| Blum 1977 Peyote, a potential ethnopharmacologic agent for alcoholism and other drug dependencies: possible biochemical rationale. Clinical Toxicology · PMID 201426 · DOI |
Case reports |
Case histories among Native American Church members and others | Peyote within the ritual n/a n/a n/a · vs n/a |
Case histories describe alcohol and opiate abuse that became asymptomatic under Indian guidance and through taking part in the ritual. The authors speculate about a shared biochemical basis. This is a 1977 paper with a theory, not a controlled test. Methods, limits and fundingOutcomes: Alcohol and opiate abstinence in case histories; proposed biochemical rationale Limitations: Case histories and speculation; very old; no control group. Funding and conflicts: US government grants. Read: abstract |
| Carstairs 2010 Peyote and mescaline exposures: a 12-year review of a statewide poison center database. Clinical Toxicology · PMID 20170392 · DOI |
Case series |
31 31 single-substance peyote or mescaline exposures reported to the California Poison Control System, 1997-2008 |
Peyote or mescaline (mostly by mouth) n/a n/a n/a · vs n/a |
97% were intentional and 97% by mouth. 16% were managed at home; the rest in a health facility. Common effects were hallucinations, fast heartbeat, agitation and enlarged pupils. Effects were usually mild or moderate and no life-threatening toxicity was reported. Methods, limits and fundingOutcomes: Effects and management Limitations: Small, one-state, phone-reported series; exposures not lab-confirmed. Funding and conflicts: Not stated in abstract. Read: abstract |
| Chan 2021 The Alkaloids from Lophophora diffusa and Other "False Peyotes". Journal of Natural Products · PMID 34264089 · DOI |
Narrative review mixed |
Review of Lophophora alkaloids | Lophophora alkaloids n/a n/a n/a · vs n/a |
Over 40 alkaloids have been isolated from the genus Lophophora, but only mescaline has been studied extensively. The major alkaloid in L. diffusa is pellotine, which was briefly marketed as a sleeping aid around 1900. Methods, limits and fundingOutcomes: Alkaloid content and pharmacology Limitations: Review. Funding and conflicts: See paper. Read: abstract |
| Dinis-Oliveira 2019 Pharmacokinetic and Pharmacodynamic Aspects of Peyote and Mescaline: Clinical and Forensic Repercussions. Current Molecular Pharmacology · PMID 30318013 · DOI |
Narrative review mixed |
Review of pharmacokinetics and pharmacodynamics | Peyote and mescaline n/a n/a n/a · vs n/a |
Effects are mainly through 5-HT2A/2C receptors and look like other psychedelics (euphoria, hallucinations, depersonalisation, psychosis) plus a sympathomimetic pattern. Mescaline is mainly broken down to trimethoxyphenylacetic acid. Most case reports had no laboratory confirmation. The authors say addiction and dependence are practically absent and most intoxications appear mild. Methods, limits and fundingOutcomes: Mechanism, metabolism, clinical effects Limitations: Narrative review; unconfirmed exposures in most case reports. Funding and conflicts: See paper. Read: abstract |
| Doesburg-van Kleffens 2023 An Overview on the Hallucinogenic Peyote and Its Alkaloid Mescaline: The Importance of Context, Ceremony and Culture. Molecules · PMID 38138432 · DOI |
Narrative review |
Review of peyote and mescaline | Peyote and mescaline n/a n/a n/a · vs n/a |
Peyote contains several alkaloids including pellotine, anhalonidine, hordenine and mescaline. Mescaline acts through the serotonin 5-HT2A receptor. Outcomes depend strongly on mindset and context, including ceremony and culture. Methods, limits and fundingOutcomes: Metabolism, mechanism, clinical studies, role of setting and culture Limitations: Narrative review. Funding and conflicts: Multi-funder consortium (see paper). Read: abstract |
| El-Seedi 2005 Prehistoric peyote use: alkaloid analysis and radiocarbon dating of archaeological specimens of Lophophora from Texas. Journal of Ethnopharmacology · PMID 15990261 · DOI |
Lab analysis lab |
2 Two archaeological peyote buttons from the Witte Museum collection (presumably Shumla Cave No. 5, Texas) |
Dried tops of Lophophora williamsii cactus top n/a n/a · vs n/a |
Radiocarbon dating gave about 3780 to 3660 BC. Mescaline was found in both samples and no other peyote alkaloid was identified. The authors say this strengthens the evidence that native North Americans recognised the plant's psychotropic properties as long as 5,700 years ago. Methods, limits and fundingOutcomes: Radiocarbon age and alkaloid content Limitations: Two museum specimens; provenance described as "presumably" Shumla Cave. Funding and conflicts: Not stated in abstract. Read: abstract |
| Eskinazi 2026 Psychedelic-induced hypomania and mania: a systematic review and meta-analysis. Molecular Psychiatry · PMID 42215638 · DOI |
Meta-analysis |
23 23 human studies of serotonergic psychedelics (including mescaline) and MDMA |
Psychedelics as a group n/a n/a n/a · vs n/a |
Rates of dysphoria/euphoria, hypomania or mania ranged from 5.8% in controlled psilocybin trials to 30% in naturalistic studies of people with bipolar disorder. Manic symptoms were usually short and self-limited. Higher risk was seen with bipolar I, family vulnerability, polysubstance use, and unsupervised or illegal use. Methods, limits and fundingOutcomes: Manic or hypomanic symptoms Limitations: Mixed designs; mescaline was one of several substances. Funding and conflicts: See paper. Read: abstract |
| Garrity 2000 Jesus, peyote, and the holy people: alcohol abuse and the ethos of power in Navajo healing. Medical Anthropology Quarterly · PMID 11224979 · DOI |
Ethnography |
Navajo healing traditions (Native American Church, Pentecostal Christianity, traditional Navajo healing) | Native American Church healing context n/a n/a n/a · vs n/a |
The Native American Church and Pentecostal Christianity are more actively involved in treating alcohol and substance abuse than traditional Navajo healing. The article describes how these traditions offer new kinds of power, social networks and personal meaning. Methods, limits and fundingOutcomes: How religious traditions respond to alcohol and substance abuse Limitations: An anthropological study; it does not measure drinking outcomes or test peyote itself. Funding and conflicts: US NIMH grants. Read: abstract |
| Halman 2024 Drug-drug interactions involving classic psychedelics: A systematic review. Journal of Psychopharmacology · PMID 37982394 · DOI |
Systematic review |
52 52 human studies from 36 reports (including 4 on mescaline) |
Classic psychedelics combined with other drugs n/a n/a n/a · vs n/a |
Combining psychedelics with other drugs gave attenuated effects, boosted effects, or no change. Apart from a few case reports, no serious adverse drug events were described. Only 4 of the 52 studies involved mescaline. Methods, limits and fundingOutcomes: Interaction effects Limitations: Mostly LSD; very few mescaline data; older studies. Funding and conflicts: See paper. Read: abstract |
| Halpern 2005 Psychological and cognitive effects of long-term peyote use among Native Americans. Biological Psychiatry · PMID 16271313 · DOI |
Cross sectional |
176 Navajo adults aged 18-45: 61 Native American Church members who regularly took peyote, 36 sober people with past alcohol dependence, 79 with minimal substance use |
Regular ceremonial peyote use in the Native American Church (real-world, not a trial) cactus (as used in ceremony) n/a n/a · vs n/a |
The peyote group showed no significant deficits on the mental health inventory or any of the ten tests compared with the minimal-use group. The former-alcohol group did show deficits. Lifetime peyote use was not linked to test performance within the peyote group. No significant deficits versus minimal-use group Methods, limits and fundingOutcomes: Rand Mental Health Inventory and ten memory, attention and executive-function tests Limitations: Observational comparison, not a trial. Participants chose their own use, so other differences may exist. The authors say the findings may not apply to illicit hallucinogen users. Funding and conflicts: US NIDA grants (government). Read: abstract |
| Klaiber 2024 Acute dose-dependent effects of mescaline in a double-blind placebo-controlled study in healthy subjects. Translational Psychiatry · PMID 39349427 · DOI |
Controlled trial |
16 16 healthy adults (8 women), Switzerland |
Pure mescaline hydrochloride given by mouth (the isolated compound, not peyote cactus), with a 5-HT2A blocker arm n/a Several single doses; amounts not reproduced here Single sessions, crossover · vs Placebo |
Effects rose with dose. Blood pressure and heart rate went up. Effects lasted from about 6 to 14 hours depending on the dose. Nausea and vomiting were frequent at the highest dose. Blocking the 5-HT2A receptor weakened and shortened the effects. Dose-dependent effects; 5-HT2A block reduced them Methods, limits and fundingOutcomes: Subjective effects, blood pressure, heart rate, side effects, blood levels up to 30 hours Limitations: Small group of healthy volunteers in a lab; purified mescaline, not the cactus; single doses. Funding and conflicts: Swiss National Science Foundation (public). Read: abstract |
| Ley 2023 Comparative acute effects of mescaline, lysergic acid diethylamide, and psilocybin in a randomized, double-blind, placebo-controlled cross-over study in healthy participants. Neuropsychopharmacology · PMID 37231080 · DOI |
Controlled trial |
32 32 healthy participants |
Pure mescaline, LSD and psilocybin given by mouth in separate sessions n/a Moderate to high single doses; not reproduced here Single sessions, crossover · vs Placebo |
Mescaline, LSD and psilocybin produced comparable experiences at equally strong doses. Mescaline lasted longest (about 11 hours on average). Mescaline caused slightly more side effects 12 to 24 hours later. Mescaline and LSD raised oxytocin. Methods, limits and fundingOutcomes: Subjective effects, blood pressure and heart rate, side effects, blood levels, oxytocin and BDNF Limitations: Healthy volunteers, small group, controlled setting; purified compounds. Funding and conflicts: Public Swiss funding; see paper for details. Read: abstract |
| Magar 2026 Indigenous Knowledge Systems & Psychedelic Science: Towards Ethical and Reciprocal Collaboration. Journal of Psychopharmacology · PMID 41618525 · DOI |
Commentary n/a |
Commentary drawing on ayahuasca, psilocybin, peyote and iboga traditions | n/a n/a n/a n/a · vs n/a |
The authors argue that research and policy must embed free, prior and informed consent, equitable benefit-sharing and Indigenous leadership, and move past tokenistic inclusion. Methods, limits and fundingOutcomes: Ethics of research with Indigenous knowledge Limitations: A commentary and argument, not data. Funding and conflicts: See paper. Read: abstract |
| Mueller 2025 Pharmacokinetics, Pharmacodynamics, and Urinary Recovery of Oral Mescaline Hydrochloride in Healthy Participants. Clinical Pharmacokinetics · PMID 40658345 · DOI |
Controlled trial |
49 49 healthy participants from two phase I trials (105 single administrations) |
Oral pure mescaline hydrochloride n/a Single doses; not reproduced here n/a · vs n/a |
Peak blood level at about 2 hours and half-life about 3.5 hours. About 53% of the dose left in urine unchanged and about 31% as the main breakdown product within 24 to 30 hours. Methods, limits and fundingOutcomes: Blood levels, effect-time modelling, urine recovery Limitations: Pooled data from healthy volunteers; purified mescaline only. Funding and conflicts: Swiss National Science Foundation (public). Read: abstract |
| Neumann 2023 Cardiac effects of ephedrine, norephedrine, mescaline, and MDMA in mouse and human atrial preparations. Naunyn-Schmiedeberg's Archives of Pharmacology · PMID 36319858 · DOI |
Lab lab |
Isolated mouse and human atrial tissue (from heart surgery) | Mescaline applied to tissue in a dish n/a n/a n/a · vs n/a |
Mescaline alone did not increase force of contraction in mouse or human atrial tissue, unlike ephedrine, norephedrine and MDMA. Methods, limits and fundingOutcomes: Force of contraction Limitations: Isolated tissue in a lab dish; does not show what happens in a living person. Funding and conflicts: See paper. Read: abstract |
| Sabe 2025 Reconsidering evidence for psychedelic-induced psychosis: an overview of reviews, a systematic review, and meta-analysis of human studies. Molecular Psychiatry · PMID 39592825 · DOI |
Meta-analysis |
131 publications on LSD, psilocybin, mescaline, DMT and MDMA | Classic psychedelics as a group n/a n/a n/a · vs n/a |
Incidence of psychedelic-induced psychosis was 0.002% in population studies, 0.2% in uncontrolled trials and 0.6% in randomised trials. In uncontrolled trials that included people with schizophrenia, 3.8% developed long-lasting psychotic symptoms. The authors call for a conservative approach. Methods, limits and fundingOutcomes: Psychosis incidence Limitations: Most studies were low quality; mescaline was one of five substances pooled. Funding and conflicts: See paper. Read: abstract |
| Shaw 2026 The Ethnopharmacological Use of Mescaline for Psychiatric Disorders: A Systematic Review. International Journal of Molecular Sciences · PMID 41977267 · DOI |
Systematic review |
10 Of 2,770 records, 66 met inclusion and only 10 were suitable for analysis; mescaline or mescaline-containing cacti |
Mescaline and mescaline-containing cacti such as peyote and San Pedro n/a n/a n/a · vs n/a |
Studies reported improvements in depression scales, well-being, nicotine dependence, alcohol use and obsessions. Hypertension, headache, nausea and vomiting were often reported. The authors say the literature is limited and of highly variable quality, so no firm conclusions are possible. Limited, variable-quality evidence Methods, limits and fundingOutcomes: Psychiatric outcomes and reported effects Limitations: Few, mixed-quality studies; no firm conclusions. Funding and conflicts: See paper. Read: abstract |
| Tabaac 2026 Psychedelic Therapy: A Primer for Primary Care Clinicians-Mescaline. American Journal of Therapeutics · PMID 42299720 · DOI |
Narrative review |
Review for clinicians | Mescaline n/a n/a n/a · vs n/a |
There is a lack of controlled clinical trials of mescaline in patient populations, and most modern safety data come from healthy volunteers. Safety in people with heart, metabolic or psychiatric conditions remains unclear. In healthy volunteers, effects were dose-dependent with moderate, temporary stimulation of the heart and blood pressure and no serious medical complications under controlled conditions. Methods, limits and fundingOutcomes: Evidence and safety of mescaline Limitations: Narrative review. Funding and conflicts: See paper. Read: abstract |
| Uthaug 2022 The epidemiology of mescaline use: Pattern of use, motivations for consumption, and perceived consequences, benefits, and acute and enduring subjective effects. Journal of Psychopharmacology · PMID 33949246 |
Survey |
452 452 English-speaking adults who had used mescaline (mostly peyote or San Pedro) |
Self-reported mescaline use, mostly cacti n/a n/a n/a · vs n/a |
Most used infrequently, for spiritual exploration or to connect with nature (74%). A small number reported craving (9%); very few reported legal or psychological problems (1% each); none sought medical attention. About half reported a psychiatric condition and most of them (over 67%) reported improvement after their most memorable experience. Methods, limits and fundingOutcomes: Use patterns, motives, effects, perceived benefits and problems Limitations: Online self-report; self-selected; recall bias; no control group; cannot show the experience caused the improvement. Funding and conflicts: US NIDA grants (government). Read: abstract |
| Vamvakopoulou 2023 Mescaline: The forgotten psychedelic. Neuropharmacology · PMID 36252614 · DOI |
Narrative review mixed |
Review of preclinical and clinical mescaline research | Mescaline n/a n/a n/a · vs n/a |
Mescaline is a serotonin 5-HT2A/2C agonist, with other receptor actions. In animals it has anxiolytic-like effects. In people it can cause euphoria, hallucinations and psychosis-like effects in naturalistic or religious settings. The authors call most intoxications mild and say research has been limited since the early 1970s. Methods, limits and fundingOutcomes: Pharmacology and behavioural effects Limitations: Narrative review; mixes animal and human work. Funding and conflicts: See paper. Read: abstract |
| Wsol 2023 Cardiovascular safety of psychedelic medicine: current status and future directions. Pharmacological Reports · PMID 37874530 · DOI |
Narrative review mixed |
Review covering psilocybin, LSD, DMT, ayahuasca and mescaline | Psychedelics n/a n/a n/a · vs n/a |
Trials in healthy volunteers point to relative cardiovascular safety. Psychedelics are linked to sympathomimetic effects, and there is a lack of data in people with cardiovascular disease. Methods, limits and fundingOutcomes: Cardiovascular safety Limitations: Narrative review. Funding and conflicts: See paper. Read: abstract |
| n/a 1994 US Code, 42 U.S.C. 1996a: Traditional Indian religious use of the peyote sacrament (American Indian Religious Freedom Act amendments) n/a · Source |
Authoritative guidance n/a |
n/a | n/a n/a n/a n/a · vs n/a |
Use, possession or transportation of peyote by an Indian for bona fide traditional ceremonial purposes in connection with the practice of a traditional Indian religion is lawful and shall not be prohibited by the United States or any State. "Indian" means a member of an Indian tribe. States may still enact reasonable traffic safety laws. Methods, limits and fundingOutcomes: Use, possession or transportation of peyote by an Indian for bona fide traditional ceremonial purposes in connection with the practice of a traditional Indian religion is lawful and shall not be prohibited by the United States or any State. "Indian" means a member of an Indian tribe. States may still enact reasonable traffic safety laws. Limitations: Read via Cornell LII on 2026-10-25 (summary of statute text, key clauses only); full section not read line by line. Not legal advice. Read: full-text |
| n/a 2019 CITES Appendices (Cactaceae listing), as reported by a 2019 news report n/a · Source |
Database record n/a |
n/a | n/a n/a n/a n/a · vs n/a |
A secondary news source states that peyote is in CITES Appendix II and that Mexico lists it as a species under special protection (NOM-059-SEMARNAT-2010). Methods, limits and fundingOutcomes: A secondary news source states that peyote is in CITES Appendix II and that Mexico lists it as a species under special protection (NOM-059-SEMARNAT-2010). Limitations: The CITES site and Species+ API could not be read (HTTP 403 / 401). NOT verified from the primary source. Read: not-read |
| n/a 2020 Iron Rope and colleagues: Sacred Peyote Conservation: Respecting Indigenous Traditions. MAPS Bulletin, Spring 2020 n/a · Source |
Community report n/a |
n/a | n/a n/a n/a n/a · vs n/a |
Describes the Indigenous Peyote Conservation Initiative (IPCI), formed in 2017 by the National Council of Native American Churches after a Peyote Research Project found peyote threatened in numbers and in quality. Authors ask outsiders to respect Indigenous sovereignty over the medicine and to support Native-led conservation. Methods, limits and fundingOutcomes: Describes the Indigenous Peyote Conservation Initiative (IPCI), formed in 2017 by the National Council of Native American Churches after a Peyote Research Project found peyote threatened in numbers and in quality. Authors ask outsiders to respect Indigenous sovereignty over the medicine and to support Native-led conservation. Limitations: Read in a search summary on 2026-10-25; the authors' list was not confirmed. The article is by Native American Church conservation workers; it is advocacy and community knowledge, not a field survey. Read: summary-only |
| n/a 2025 Saldana S, Texas Public Radio / Texas Standard: Native American Church faces declining peyote supply in Texas (23 Aug 2025) n/a · Source |
News report n/a |
n/a | n/a n/a n/a n/a · vs n/a |
Reports that peyote grows mainly in South Texas and that supply is declining because of development and habitat loss, over-harvesting and poaching. Only four active licences to harvest and distribute peyote in Texas were reported. Native American Church members describe peyote as sacred ("God in plant form"). Methods, limits and fundingOutcomes: Reports that peyote grows mainly in South Texas and that supply is declining because of development and habitat loss, over-harvesting and poaching. Only four active licences to harvest and distribute peyote in Texas were reported. Native American Church members describe peyote as sacred ("God in plant form"). Limitations: News interview, not peer reviewed. The licence count was not confirmed against an official source. Read: full-text |
| n/a 2026 IUCN Red List: Lophophora williamsii (species ID 151962), as reported through Kew POWO and other summaries n/a · Source |
Database record n/a |
n/a | n/a n/a n/a n/a · vs n/a |
Secondary summaries (a web search of Kew POWO and other pages) report the IUCN Red List category as Vulnerable. The assessment year and criteria were not found. Methods, limits and fundingOutcomes: Secondary summaries (a web search of Kew POWO and other pages) report the IUCN Red List category as Vulnerable. The assessment year and criteria were not found. Limitations: The IUCN page returned HTTP 403 and could not be read. NOT verified from the primary source. Read: not-read |
| n/a 2026 US eCFR: 21 CFR 1308.11 Schedule I (mescaline and peyote entries) n/a · Source |
Authoritative guidance n/a |
n/a | n/a n/a n/a n/a · vs n/a |
Mescaline (code 7381) and peyote (code 7415) are listed in Schedule I. Peyote is defined as all parts of the plant presently classified botanically as Lophophora williamsii Lemaire, whether growing or not, the seeds, any extract, and every compound, salt, derivative, mixture or preparation of it. Methods, limits and fundingOutcomes: Mescaline (code 7381) and peyote (code 7415) are listed in Schedule I. Peyote is defined as all parts of the plant presently classified botanically as Lophophora williamsii Lemaire, whether growing or not, the seeds, any extract, and every compound, salt, derivative, mixture or preparation of it. Limitations: Entries read 2026-10-25 via the eCFR API; the full schedule was not read. Not legal advice. Read: full-text |
| n/a 2026 US eCFR: 21 CFR 1307.31 Native American Church n/a · Source |
Authoritative guidance n/a |
n/a | n/a n/a n/a n/a · vs n/a |
The listing of peyote in Schedule I does not apply to the nondrug use of peyote in bona fide religious ceremonies of the Native American Church, and members so using peyote are exempt from registration. Anyone who manufactures peyote for, or distributes it to, the Church must register annually and follow all other legal requirements. Methods, limits and fundingOutcomes: The listing of peyote in Schedule I does not apply to the nondrug use of peyote in bona fide religious ceremonies of the Native American Church, and members so using peyote are exempt from registration. Anyone who manufactures peyote for, or distributes it to, the Church must register annually and follow all other legal requirements. Limitations: Text read on 2026-10-25 via the eCFR API (version dated 2026-10-20). Not legal advice. Read: full-text |
| n/a 2026 UN Convention on Psychotropic Substances 1971 and the INCB position on plants, as summarised by ICEERS n/a · Source |
Secondary summary n/a |
n/a | n/a n/a n/a n/a · vs n/a |
A secondary summary states that mescaline is in Schedule I of the 1971 Convention but that plants such as peyote are not themselves under international control, and that the INCB view has been interpreted differently by courts in different countries. Methods, limits and fundingOutcomes: A secondary summary states that mescaline is in Schedule I of the 1971 Convention but that plants such as peyote are not themselves under international control, and that the INCB view has been interpreted differently by courts in different countries. Limitations: Secondary, advocacy-oriented summary. The UN text and INCB wording were not read. NOT verified from the primary source. Read: summary-only |
| n/a 2026 PubChem: Mescaline (CID 4076) n/a · Source |
Authoritative guidance n/a |
n/a | n/a n/a n/a n/a · vs n/a |
CID 4076; formula C11H17NO3; IUPAC name 2-(3,4,5-trimethoxyphenyl)ethanamine; molecular weight 211.26 (PubChem REST API, retrieved 2026-10-25). Methods, limits and fundingOutcomes: CID 4076; formula C11H17NO3; IUPAC name 2-(3,4,5-trimethoxyphenyl)ethanamine; molecular weight 211.26 (PubChem REST API, retrieved 2026-10-25). Limitations: Database record, not a study. Read: full-text |
| n/a 2026 GBIF Backbone Taxonomy: Lophophora williamsii (Lem. ex Salm-Dyck) J.M.Coult. n/a · Source |
Authoritative guidance n/a |
n/a | n/a n/a n/a n/a · vs n/a |
Accepted species, family Cactaceae, usage key 5384220 (API match EXACT, retrieved 2026-10-25). Distribution records list SW Texas (USA) and the Mexican states Chihuahua, Coahuila, Durango, Jalisco, Nuevo Leon, San Luis Potosi, Tamaulipas and Zacatecas (Catalogue of Life entry). Methods, limits and fundingOutcomes: Accepted species, family Cactaceae, usage key 5384220 (API match EXACT, retrieved 2026-10-25). Distribution records list SW Texas (USA) and the Mexican states Chihuahua, Coahuila, Durango, Jalisco, Nuevo Leon, San Luis Potosi, Tamaulipas and Zacatecas (Catalogue of Life entry). Limitations: Kew Plants of the World Online was blocked (HTTP 403) so was not read directly. Read: full-text |
What we do not know yet
- No modern trial of peyote cactus in any illness.
- No controlled data for alcohol use disorder, depression or anxiety with peyote or mescaline.
- Safety in pregnancy, breastfeeding, heart disease and psychiatric illness is not established.
- IUCN, CITES and UN/INCB entries were not read from primary pages.
- Indigenous voices: the section on tradition and conservation needs review by Native American Church and Indigenous representatives.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue. A person reads each one before it changes any rating or safety wording.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Other 4
Memory, attention and executive-function test scores
No change in trials
Scores on ten standard tests of memory, attention and planning.
Low certaintyResults and what it means
Why it was measured
To check whether regular use of a hallucinogen is linked to lasting thinking problems.
Statistical vs. clinical meaning
No significant deficits were found. Numbers were not reported in the abstract.
Safety implication
Not a safety guarantee for other groups.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | The regular-peyote group did not differ significantly from the minimal-use group on any of the ten tests. | 61 Native American Church members who regularly took peyote | Regular ceremonial peyote use (not a trial) |
Rand Mental Health Inventory score
No change in trials
A questionnaire that rates anxiety, depression, behavioural control and well-being.
Low certaintyResults and what it means
Why it was measured
To compare general mental health between groups.
Statistical vs. clinical meaning
Statistical comparison only; no effect sizes in the abstract.
Safety implication
None beyond the above.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | No significant difference between peyote users and the minimal-use group; the former-alcohol group scored worse (p < .05 on every scale). | 176 Navajo adults in three groups | Regular ceremonial peyote use (not a trial) |
Blood pressure
Raised in trials
The force of blood against artery walls.
Low certaintyResults and what it means
Why it was measured
Stimulant-like drugs can raise it.
Statistical vs. clinical meaning
Statistically significant in a small crossover trial; numbers not given in the abstract.
Safety implication
Possible concern for people with high blood pressure or heart disease; not studied.
| Study | Result | People | Product |
|---|---|---|---|
| 13 | Systolic and diastolic blood pressure rose at doses above the lowest tested, with no difference between the middle and top doses. | 16 healthy adults | Pure mescaline hydrochloride, single sessions, versus placebo |
Heart rate
Raised in trials
Heartbeats per minute.
Low certaintyResults and what it means
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 7
- It is a strong psychedelic with long-lasting effects. Mescaline can cause hallucinations, euphoria, fear, confusion and psychosis-like effects. Effects in healthy volunteers lasted about 6 to 14 hours depending on dose, longer than psilocybin or LSD. Peyote is not a treatment for any condition. Controlled trial 13 14 6
- Mental health risks: psychosis and mania. In pooled studies of psychedelics (mescaline was one of several), psychedelic-induced psychosis was rare in people without psychosis history, but 3.8% of people with schizophrenia in uncontrolled trials developed lasting psychotic symptoms. Manic symptoms were usually short but more common in people with bipolar disorder and with unsupervised or illegal use. People with these conditions or family history should not take psychedelics without medical advice. Meta-analysis 18 9
- Heart and blood pressure. Pure mescaline raised blood pressure and heart rate in healthy volunteers. Safety in people with heart disease is not known. Controlled trial 13 23 20
- Poison-center cases were mostly mild to moderate. In 31 single-substance cases in California over 12 years, effects were mostly mild or moderate (hallucinations, fast heartbeat, agitation, enlarged pupils) and no life-threatening toxicity was reported. Most reports in the wider literature had no lab confirmation of what was taken. Case series 4 6
- Nausea and vomiting are common. Nausea and vomiting were frequent at the highest dose in the healthy-volunteer trial, and the 2026 systematic review also found them often reported. Controlled trial 13 19
- Peyote is a protected plant and a sacrament. The plant is declining in Texas and is reported as Vulnerable on the IUCN Red List. Native American Church authors ask outsiders not to take peyote and to support Indigenous-led conservation. See the Overview tab. Authoritative guidance 27 26 28
- It is illegal in most places; a US religious exemption exists. Peyote and mescaline are Schedule I in the United States, with a federal exemption for bona fide Native American Church ceremonial use. Laws differ by country and change. This is not legal advice. Authoritative guidance 29 30 24
Side effects 9
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Hallucinations, altered perception, euphoria Duration rose with dose in volunteers. | Expected effect | moderate Reversible in trials as effects wear off | Controlled trial 13 14 |
| Nausea and vomiting Often reported in ceremonial use too, per the systematic review. | Frequent at the highest dose in one trial; vomiting in 1 of 31 poison-center cases | mild Reversible | Controlled trial 13 4 |
| Raised blood pressure and heart rate Not studied in people with heart disease. | Seen in healthy volunteers; no rate given in the abstract | mild Reversible in the trial | Controlled trial 13 23 |
| Agitation and enlarged pupils Effects were usually mild or moderate. | Common in poison-center cases | mild Usually reversible | Case series 4 |
| Headache Quality of included studies was variable. | Often reported in the systematic review | mild Unknown | Systematic review 19 |
| Later-day side effects (12 to 24 hours) | Slightly more than LSD or psilocybin at equal strength in one trial | mild Reversible | Controlled trial 14 |
| Psychosis-like effects or lasting psychosis Mescaline was one of five substances pooled. | Rare in general populations; higher in people with schizophrenia in uncontrolled trials | severe Unknown | Meta-analysis 18 22 |
| Mania or hypomania Higher in bipolar disorder and unsupervised or illegal use. | Ranged from 5.8% to 30% depending on study type and group (psychedelics as a group) | moderate Usually short and self-limited | Meta-analysis 9 |
| Dependence or craving Low potential for abuse is the authors' reading; not proof. | Craving reported by 9% of 452 survey respondents; one review calls dependence practically absent | mild Unknown | Survey 21 6 |
Liver
No source read reported liver injury linked to peyote or mescaline. This is a gap, not proof of safety.
How often. Not studied.
Monitoring. No monitoring advice read.
This is a safety connection. It is not evidence that Peyote supports liver health.
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Prescription medicines in general (antidepressants, antipsychotics, mood stabilisers, sedatives) prescription | Mixed: some drugs weaken psychedelic effects, others strengthen them. | A 2024 systematic review found attenuated, potentiated and unchanged effects across classic psychedelics. Only 4 of 52 studies were on mescaline, and apart from a few case reports no serious adverse events were described. | Systematic review Low certainty 11 | Ask a doctor or pharmacist before combining anything with peyote or mescaline. Do not stop prescribed medicines on your own. |
| Serotonergic medicines and stimulants prescription | Mescaline acts on serotonin receptors and has a stimulant-like side. | No mescaline-specific trial of this combination was read. The effect is inferred from the receptor action and from broader psychedelic reviews. | Theory Not enough evidence 6 11 | Treat as unknown and ask a clinician. |
| Alcohol and other recreational drugs recreational | Unknown for peyote. | The interaction review included recreational drugs in general, but no peyote-specific finding was read. | Systematic review Not enough evidence 11 | Unknown. Combining substances raises uncertainty. |
Who should check first 5
| Situation | Advice | Evidence |
|---|---|---|
| Pregnancy and breastfeeding | Not enough data. A 2026 scoping review found only one eligible human study on mescaline or peyote in pregnancy and said absence of data is not evidence of safety. No breastfeeding data were read. | Scoping review 1 |
| Schizophrenia, psychosis history, bipolar disorder, or a family history of these | Higher risk of psychotic or manic symptoms with psychedelics. Talk to a doctor. | Meta-analysis 18 9 |
| Heart disease or high blood pressure | Safety is unknown. Mescaline raised blood pressure and heart rate in healthy volunteers. | Controlled trial 13 23 20 |
| Driving or operating machinery | Do not drive during effects, which can last many hours. No driving study of peyote was read. | Controlled trial 13 14 |
| Children and teenagers | No safety data read for children. Poison-center and review sources report adolescent and young-adult illicit use. | Review 6 |
Overdose, product quality and regulators
Summary. Cactus top (the "button") is the part used. In the poison-center series, effects were usually mild or moderate and no life-threatening toxicity was reported. Most published case reports lacked laboratory confirmation of what was taken.
Animal. Not reviewed in depth; a review reports anxiolytic-like effects in animals.
Human doses studied. Amounts are not covered on this page.
High dose or long term signals. At the highest tested pure-mescaline dose, nausea and vomiting were frequent and tolerability was lower. Long-term safety was not studied except in one observational study of Navajo ceremonial users, which found no memory, attention or mental health deficits.
Overdose response. Not described in the sources read beyond poison-center management of mild to moderate effects.
Genotoxicity. Not read.
Toxic plant parts. Not compared in the sources read.
Mescaline content is not predictable from the plant name. A lab study found peyote specimens that contained no mescaline, and cacti sold or seized under other names are not guaranteed to be Lophophora williamsii.
Variable or absent mescaline. Some L. williamsii specimens contained no mescaline in one lab study, and L. diffusa ("false peyote") has pellotine as its main alkaloid. 2 5
| Body | Action | Date |
|---|---|---|
| US Drug Enforcement Administration (21 CFR 1308.11) (United States) | Lists peyote (all parts of Lophophora williamsii, whether growing or not, seeds and extracts) and mescaline in Schedule I. source | 2026-10-25 |
| US Drug Enforcement Administration (21 CFR 1307.31) (United States) | The Schedule I listing does not apply to the nondrug use of peyote in bona fide religious ceremonies of the Native American Church; members so using it are exempt from registration. Anyone who manufactures or distributes peyote to the Church must register annually. source | 2026-10-25 |
| US Congress, American Indian Religious Freedom Act amendments (42 U.S.C. 1996a) (United States) | States that use, possession or transportation of peyote by an Indian (a member of an Indian tribe) for bona fide traditional ceremonial purposes in connection with a traditional Indian religion is lawful and shall not be prohibited by the United States or any State. States may enforce reasonable traffic safety laws. source | 2026-10-25 |
When to get medical help
- Chest pain, a racing or irregular heartbeat, fainting or trouble breathing: call emergency services (911 in the US, 112 in the EU, 999 in the UK, 000 in Australia).
- Severe confusion, extreme agitation, seeing or hearing things that will not stop, thoughts of harming yourself or others: call emergency services.
- Repeated vomiting that does not stop, seizure, or being very hard to wake: call emergency services.
- For advice after a possible poisoning in the US, Poison Help is 1-800-222-1222. Other countries have their own poison centre numbers; look up your national line.
If someone may be poisoned or in a crisis, contact a clinician or emergency service straight away. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
What is peyote?
Is peyote the same as mescaline?
Is peyote a medicine?
What do studies of Native American Church members show?
One study of 61 Navajo members who took peyote regularly found no memory, attention or mental health deficits compared with Navajos who used little. It is a single observational study and may not apply to illicit users.
Does peyote help with alcohol use?
What are the risks?
Is it safe in pregnancy or with heart disease?
Is peyote addictive?
Is peyote endangered?
Is peyote legal?
Why do Native American Church authors ask outsiders to respect peyote?
How long has peyote been used?
Radiocarbon dating of two Texas museum specimens put them at roughly 3780 to 3660 BC, and both held mescaline. The authors say native North Americans knew the plant's effects as long as 5,700 years ago.
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- AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
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- First published
- 2026-10-25
- Last substantive update
- 2026-10-25
- How we research
- We searched PubMed and read the abstracts of 22 papers, read US federal rules and statute text for the legal entries, and checked the plant name in GBIF and mescaline in PubChem. IUCN, CITES, Kew POWO and UN/INCB pages could not be read, so those entries are marked unconfirmed. Certainty ratings are the compiler's own reading.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
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Sources 33
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
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- Garrity JF. Jesus, peyote, and the holy people: alcohol abuse and the ethos of power in Navajo healing.. Medical Anthropology Quarterly. 2000. PMID 11224979. DOI 10.1525/maq.2000.14.4.521. (abstract)
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- Klaiber A, Schmid Y, Becker AM, Straumann I, et al. Acute dose-dependent effects of mescaline in a double-blind placebo-controlled study in healthy subjects.. Translational Psychiatry. 2024. PMID 39349427. DOI 10.1038/s41398-024-03116-2. (abstract)
- Ley L, Holze F, Arikci D, Becker AM, et al. Comparative acute effects of mescaline, lysergic acid diethylamide, and psilocybin in a randomized, double-blind, placebo-controlled cross-over study in healthy participants.. Neuropsychopharmacology. 2023. PMID 37231080. DOI 10.1038/s41386-023-01607-2. (abstract)
- Magar V, Robbins M, Fernandez Lobo Blanco OML, Ali IL, et al. Indigenous Knowledge Systems & Psychedelic Science: Towards Ethical and Reciprocal Collaboration.. Journal of Psychopharmacology. 2026. PMID 41618525. DOI 10.1177/02698811251387104. (abstract)
- Mueller L, Klaiber A, Ley L, Becker AM, et al. Pharmacokinetics, Pharmacodynamics, and Urinary Recovery of Oral Mescaline Hydrochloride in Healthy Participants.. Clinical Pharmacokinetics. 2025. PMID 40658345. DOI 10.1007/s40262-025-01544-x. (abstract)
- Neumann J, Azatsian K, Hoehm C, Hofmann B, et al. Cardiac effects of ephedrine, norephedrine, mescaline, and MDMA in mouse and human atrial preparations.. Naunyn-Schmiedeberg's Archives of Pharmacology. 2023. PMID 36319858. DOI 10.1007/s00210-022-02315-2. (abstract)
- Sabe M, Sulstarova A, Glangetas A, De Pieri M, et al. Reconsidering evidence for psychedelic-induced psychosis: an overview of reviews, a systematic review, and meta-analysis of human studies.. Molecular Psychiatry. 2025. PMID 39592825. DOI 10.1038/s41380-024-02800-5. (abstract)
- Shaw J, Yong A, Lee J, Cheng J, et al. The Ethnopharmacological Use of Mescaline for Psychiatric Disorders: A Systematic Review.. International Journal of Molecular Sciences. 2026. PMID 41977267. DOI 10.3390/ijms27073081. (abstract)
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- Uthaug MV, Davis AK, Haas TF, Davis D, et al. The epidemiology of mescaline use: Pattern of use, motivations for consumption, and perceived consequences, benefits, and acute and enduring subjective effects.. Journal of Psychopharmacology. 2022. PMID 33949246. (abstract)
- Vamvakopoulou IA, Narine KAD, Campbell I, Dyck JRB, et al. Mescaline: The forgotten psychedelic.. Neuropharmacology. 2023. PMID 36252614. DOI 10.1016/j.neuropharm.2022.109294. (abstract)
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- n/a. US Code, 42 U.S.C. 1996a: Traditional Indian religious use of the peyote sacrament (American Indian Religious Freedom Act amendments). n/a. 1994. (full-text)
- n/a. CITES Appendices (Cactaceae listing), as reported by a 2019 news report. n/a. 2019. (not-read)
- n/a. Iron Rope and colleagues: Sacred Peyote Conservation: Respecting Indigenous Traditions. MAPS Bulletin, Spring 2020. n/a. 2020. (summary-only)
- n/a. Saldana S, Texas Public Radio / Texas Standard: Native American Church faces declining peyote supply in Texas (23 Aug 2025). n/a. 2025. (full-text)
- n/a. IUCN Red List: Lophophora williamsii (species ID 151962), as reported through Kew POWO and other summaries. n/a. 2026. (not-read)
- n/a. US eCFR: 21 CFR 1308.11 Schedule I (mescaline and peyote entries). n/a. 2026. (full-text)
- n/a. US eCFR: 21 CFR 1307.31 Native American Church. n/a. 2026. (full-text)
- n/a. UN Convention on Psychotropic Substances 1971 and the INCB position on plants, as summarised by ICEERS. n/a. 2026. (summary-only)
- n/a. PubChem: Mescaline (CID 4076). n/a. 2026. (full-text)
- n/a. GBIF Backbone Taxonomy: Lophophora williamsii (Lem. ex Salm-Dyck) J.M.Coult.. n/a. 2026. (full-text)