Ayahuasca

Amazonian ritual and healing traditions

A 2021 pharmacological review describes ayahuasca as part of ritual and healing practices in several Indigenous groups of the Amazon basin and among other populations of South America, where it is used to access invisible worlds. A 2026 systematic review states that the brew has been used in Central and South America for centuries. The sources reviewed give no date for the earliest use and no documented line of descent, so the antiquity of any particular practice is not established here.

Ethnographic work among the Shipibo-Konibo of Ucayali, Peru, drawing on 15 years of fieldwork, treats ayawaska use as inseparable from a linguistic, cosmological and spiritual framework. Its authors write that Indigenous use cannot be considered apart from that framework. The sources reviewed describe the Shipibo-Konibo but do not support an account of Quechua, Tukano or other peoples' practices, which differ from one another and are not summarized here.

Brazilian ayahuasca religions

An encyclopedia entry dates the founding of the União do Vegetal (UDV) to July 22, 1961, in Porto Velho, Brazil, by José Gabriel da Costa, known as Mestre Gabriel. It describes sacramental consumption of Hoasca tea in ceremonial sessions and reports about 20,000 members in more than 216 congregations in Brazil and several other countries. It presents the movement's own account and does not report outside studies of its members.

A 2015 article by Marcelo Simão Mercante dates Barquinha to 1945, founded by Daniel Pereira de Matos in Rio Branco, Acre. The article notes that the literature has emphasized Indigenous elements of these religions and argues that Barquinha is better classed as Afro-Amazonian, giving African influences weight alongside Indigenous and Brazilian ones. A cross-sectional study places ayahuasca rituals in a Santo Daime church, the Centro Luz Divina, in Brazil. The sources reviewed do not supply a verified founding account for Santo Daime.

Spread beyond the Amazon

A 2021 review reports that the psychoactive and visionary effects of ayahuasca have been highly sought by the shamanic tourism community, which popularized the brew globally and led to a cultural distancing from traditional cosmological meanings such as purging. A 2012 review notes that the brew is now taken globally, and a 2026 review refers to drug tourism and growing scientific interest. A 2020 event description by the Chacruna Institute reports an ethnomusicologist's observation that ceremonial singing shifted when Indigenous communities began hosting Western visitors.

Names and spellings

Ayahuasca is the most common name in the biomedical and anthropological sources reviewed. The Shipibo-Konibo ethnography uses the spelling ayawaska, and the UDV entry calls its sacrament Hoasca tea. Sources therefore differ in spelling, and in whether the word names a brew, a ceremony or a wider practice. This page uses ayahuasca for the brew and for the practices around it, and names the specific tradition wherever a source does.

Composition in scientific usage

A controlled pharmacology study describes ayahuasca as a tea commonly obtained from Banisteriopsis caapi and Psychotria viridis. It combines N,N-dimethyltryptamine (DMT), an orally labile psychedelic with 5-HT2A agonist activity, with monoamine oxidase (MAO) inhibiting beta-carboline alkaloids: harmine, harmaline and tetrahydroharmine. A study of a Santo Daime church confirmed the botanical identities and the presence of these alkaloids in the plants and the brew used there.

Analogs and substitutes

A 2012 review reports sales of ayahuasca compounds on the internet and the substitution of related botanical preparations, termed anahuasca, or synthetic compounds, termed pharmahuasca. These are not the same as traditional or church brews. The sources reviewed do not compare their effects or hazards with those of traditional brews, so findings from one should not be carried over to another.

Amazonian ceremonial contexts

According to the Chacruna event description, singing is central to Indigenous ceremony and is how healers communicate with the spirit of the plants. Purging and emesis carry cultural meaning in Amazonian traditions, according to a 2021 review. At a retreat in the Peruvian Amazon, Shipibo healers and their international clients drew on purging and visions to interpret illness and healing, with some taking the idea of a plant teacher literally and others as metaphor. This page does not describe preparation or sacred knowledge.

Church sessions in Brazil

The UDV entry describes members drinking Hoasca tea in ceremonial sessions intended to deepen spiritual understanding and connection. Research has also been conducted with members of a Santo Daime church who take part in ritual use. A 2026 chapter notes that communities using psychedelics as religious sacraments have developed their own frameworks for safety and their own ideas of risk and harm. The sources reviewed do not describe session structure in a form this page reproduces, and practice differs between churches.

Retreat, neo-shamanic and clinical settings

A 2024 survey of 7,576 people who had used ayahuasca in religious, traditional or non-traditional settings in over 50 countries shows how widely the practice has spread. A 2026 systematic review found that most prospective studies enrolled unselected volunteers attending retreat centers. In clinical research the brew has been given in controlled settings, including an inpatient psychiatric unit in an open-label study and a placebo-controlled trial, described later on this page.

Spiritual, relational and healing meanings

Shamans, neo-shamans, atheists and others describe gaining special knowledge from drinking ayahuasca, which supports the cross-cultural idea of ayahuasca as a plant teacher. Secular participants tend to read this metaphorically and animists literally. The UDV entry describes its sessions as intended to enhance spiritual understanding. The Shipibo-Konibo ethnography asks that the perspectives of Shipibo visionary healers be given priority in how such use is understood.

Uses that researchers have examined

Clinical research has concentrated on depression, including treatment-resistant depression and suicidal thoughts. Prospective studies of mainly retreat attendees noted changes in wellbeing, depressive symptoms, substance misuse, cognitive flexibility, personality and prosocial behavior, but the authors describe these as preliminary. A 2012 pharmacology review proposed mechanisms by which harmine might reduce relapse to alcohol and cocaine misuse, which was a hypothesis and not a finding. Haupt and colleagues found no prospective studies on physical health conditions specifically.

Randomized trial in treatment-resistant depression

Palhano-Fontes and colleagues ran a parallel-arm, double-blind, placebo-controlled trial in 29 patients with treatment-resistant depression who received a single dose of ayahuasca or placebo. Depression scores were lower with ayahuasca on the Montgomery-Asberg scale at days 1 and 2 (p = 0.04) and at day 7 (p < 0.0001), with between-group effect sizes of 0.84 at day 1 and 1.49 at day 7. Response at day 7 was 64% against 27%, and remission was 36% against 7%, a trend (p = 0.054).

A secondary analysis of the same trial found that the difference in suicidality between groups trended toward significance (p = 0.088), with medium between-group effect sizes (0.56 to 0.67) and large within-group reductions on ayahuasca. A 2022 Canadian task force graded the two pilot studies of single-dose ayahuasca for treatment-resistant depression as Level 3 evidence and noted that small samples and functional unblinding were major limitations of all psychedelic studies. It concluded that evidence for psychedelics in major depression remained low-level.

Open-label and observational studies

An open-label study of 17 inpatients with recurrent depression, with no control group, reported lower depression scores from 80 minutes to day 21 and increased blood flow in regions linked to mood regulation. Its authors asked for replication in blinded trials. A 2024 cross-sectional survey of 7,576 people found that more ayahuasca uses were associated with better current mental health, whereas acute extreme fear and integration difficulties were associated with worse outcomes. Associations in a self-selected survey do not show cause.

The 2026 systematic review of 18 prospective studies found population-level improvements but also subsets of participants with persisting psychiatric complications linked to use. It listed small samples, unstandardized dosages, no control groups and nonrandomized designs as limits. A cross-sectional study of 48 people in a Santo Daime church found no evidence of cognitive decline among long-term users compared with controls.

Pharmacology and mechanism

DMT is broken down rapidly after oral intake unless the MAO-inhibiting harmine slows it. In a double-blind placebo-controlled study of 18 volunteers experienced with psychedelics, ayahuasca produced marked subjective effects peaking between 1.5 and 2 hours. Plasma harmine levels were negligible and the usual MAO-inhibitor metabolite pattern was absent, which the authors took to suggest a predominantly peripheral action of harmine, enough to prevent first-pass metabolism of DMT. Harmine also acts at other targets, according to a 2012 review.

Indigenous perspectives and differing ontologies

The Shipibo-Konibo ethnography criticizes psychological and biomedical studies of ayawaska for what it calls ethnographic thinness and conceptual impositions, and warns that they risk reducing Indigenous ontologies to psychological projections. Its authors do not reject Western findings outright but argue for dialogue that preserves Amazonian sovereignty. A medical anthropology study of a retreat in the Peruvian Amazon describes ontological collisions between Shipibo healers and international clients over whether a plant can teach.

Tourism and change in practice

The Chacruna event description reports that contact with Western visitors brought positive cultural revitalization alongside negative impacts on local communities, and that Indigenous knowledge was often reinterpreted through Western psychological frameworks. A 2021 review states that tourist demand for visionary effects led to cultural distancing from traditional meanings. The sources reviewed do not address plant sustainability or prices, so those debates are not assessed here.

Interactions with antidepressants and other drugs

A 1998 paper warned that the MAO-inhibiting harmala alkaloids in ayahuasca combined with selective serotonin reuptake inhibitors (SSRIs) may induce a serotonin syndrome with potentially grave outcome, and advised caution with certain pharmaceutical drugs. A 2026 modeling study, built from data on six volunteers, simulated that fluoxetine and paroxetine raise harmine exposure and moderately raise DMT concentrations. Its authors judged the interaction clinically relevant, although it is a simulation and not a clinical trial.

A 2024 systematic thematic review of 78 articles reported that harmala alkaloid toxicity at higher doses may increase with co-administration of certain medications, and that animal studies at higher doses showed abortifacient and teratogenic effects. The authors caution that high-dose animal findings may not extrapolate to human use of plant preparations.

Cardiovascular and physical effects

In the 18-volunteer pharmacology study, diastolic blood pressure rose by 9 mm Hg at the higher dose at 75 minutes, while systolic pressure and heart rate rose moderately without reaching significance. Vomiting was the only adverse effect recorded in the open-label depression study, reported by 47% of its 17 participants. A 2021 review treats purging and emesis as a major pharmacological action as well as a culturally meaningful one.

Psychiatric risks and deaths

Case reports describe psychosis after ceremonial use, including an enduring psychotic episode with violence toward a relative in a previously well man, whose recovery was sustained at 18 months. A 2026 meta-analysis of psychedelic-induced mania across several substances, including DMT and ayahuasca, found higher risk in bipolar I disorder, familial vulnerability, polysubstance use and unsupervised use, and reported no ayahuasca-specific rate. The White review states that serious adverse effects are rarely reported in healthy populations.

A 2025 review of DMT fatalities identified three earlier reports, all judged accidental, two of them in ayahuasca ceremonies, and added two UK deaths involving polydrug use, including drugs that raise serotonergic activity. A 2005 case report described a 25-year-old found dead after consuming herbal extracts that contained 5-methoxy-DMT; the cause was recorded as hallucinogenic amine intoxication, with manner of death undetermined. These reports give no rate of death.

Suitability and care boundaries

Sources reviewed do not provide a validated screening standard for ceremonial or retreat settings. The 2026 prospective review and a church-community study both point to unmet research needs on harms. Anyone taking antidepressants or other serotonergic medication, with psychosis, bipolar disorder or cardiovascular disease, or who is pregnant, should consult a clinician and not rely on ceremony hosts. Ayahuasca should not delay or replace necessary care.