Ayahuasca: Traditional Preparation, Research and Safety

Safety first. Ayahuasca contains plant compounds that block an enzyme called monoamine oxidase (MAO). A 2026 case report describes a man who developed severe serotonin syndrome and needed a breathing tube and intensive care after taking ayahuasca and then over-the-counter dextromethorphan and diphenhydramine. He recovered. [1] Serotonin syndrome is a dangerous build-up of serotonin activity; NIDA says it is usually mild but can be life-threatening in rare cases. [2] If someone feels very unwell after taking ayahuasca, call 911 (US) or local emergency services; US Poison Help is 1-800-222-1222 (poison help by country). Never stop or change a prescribed medicine on your own; talk with the prescriber (talking with a health professional).

This page is information only. It does not describe how ayahuasca is made, how much is taken, or how ceremonies are run, and it does not recommend its use.

What ayahuasca is

Ayahuasca is a traditional brew used for therapeutic and ritual purposes by Indigenous groups of northwestern Amazonian countries such as Brazil, Peru, Colombia and Ecuador. It is made from a vine and a leafy plant: the vine Banisteriopsis caapi supplies beta-carboline compounds such as harmine, and the leaves of the shrub Psychotria viridis supply dimethyltryptamine (DMT). [3] A third plant, Diplopterys cabrerana, is also named as a DMT source in the medical literature. [1] The brew is not a single chemical. It is a preparation made from plants, which differs from DMT on its own; see DMT vs ayahuasca and traditional preparations vs isolated compounds.

Why the two plants matter together

A pharmacokinetic modeling study explains that harmine blocks the MAO-A enzyme that would otherwise break DMT down quickly after it is swallowed, which allows more DMT to reach the brain. [4] That is also why the interaction risk above exists. It is a computer model built from rat and human data, not a clinical test. Reviews also note that brews made with substitute plants or with extracted or lab-made compounds (sometimes called "anahuasca" or "pharmahuasca") are a different thing from the traditional preparation. [5][6] Plant profiles: ayahuasca vine and chacruna.

Traditional and religious contexts

Ayahuasca was originally used by Indigenous shamans for spirit communication and healing, and several Brazilian churches use it as a sacrament. [7] Members of one of them, the Santo Daime, consider it a medicinal sacrament. [8] Each tradition has its own meaning and rules, which belong to its people and are not reproduced here. Indigenous authors and scholars have raised concerns about outside demand, patenting and the medicalization of ayahuasca without respect for Indigenous rights and the sustainability of the plants. [9][10] See Indigenous traditions, ethics and conservation.

What research shows

Evidence labels used here: promising but limited (some controlled data, small or short) and insufficient evidence (not enough to judge). Observational surveys cannot show cause and effect.

Risks and who should be most careful

• Medicine interactions. Serotonin-affecting medicines and some over-the-counter products can combine dangerously with ayahuasca. A critical review of reported severe cases concluded that previous heart and liver disease and current use of serotonin-affecting medicines look like contraindications. [6] See interactions by drug class and psychedelic drug interactions.
• Common side effects. In the Global Ayahuasca Survey (an online, self-selected survey of 10,836 people in more than 50 countries), 69.9% reported acute physical effects, mainly vomiting, and 2.3% needed later medical attention. [13]
• Mental health effects. In the same survey 55.9% reported adverse mental health effects in the following weeks or months, though about 88% saw them as part of a positive process, and about 12% sought professional support. They were linked to anxiety disorders and to the strength of the spiritual experience. [13]
• Unsupervised use. Physical adverse effects in that survey were linked to taking ayahuasca in a non-supervised context. [13]
• Heart disease. A cardiovascular review says data are lacking for people with cardiovascular disease. [14]
• Psychosis or bipolar disorder. Clinical research excludes these groups as a precaution. [2]
• Pregnancy. Proper evidence not found for ayahuasca specifically; NIDA says effects of psychedelics in pregnancy are not well understood. [2]

Quality and labeling

Proper evidence not found from a regulator on the contents of ayahuasca offered outside research. One Uruguayan study analyzed samples from two groups and found a typical alkaloid composition and no adulterants, but it covers only those samples. [15] Do not generalize one sample to others. See evaluating retreat claims.

Legal status

This is not legal advice, and laws change. In the United States, federal Schedule I (21 CFR 1308.11) lists dimethyltryptamine; the section text does not name ayahuasca or Banisteriopsis caapi, and how other US law treats the brew was not verified (US eCFR, read 2026-10-22). [16] A 2012 review describes how Brazil moved from prohibition to a 2010 national resolution setting rules for religious and ritual use. [17] We did not read Brazilian law itself, so that is background, not a statement of current law. Other countries: not verified. See psychedelic legal status by country.