Is Ayahuasca Dangerous? The Real Risks, Explained

Ayahuasca is not risk-free, but the danger picture is more specific than the headlines suggest. The brew itself has rarely been shown to directly kill a healthy, properly screened person. Most serious harm clusters around a handful of avoidable factors: dangerous drug and medication interactions, pre-existing heart or psychiatric conditions, added plants like tobacco, and unregulated settings with no screening and no one trained to respond. Understanding those risks, and choosing accordingly, is what separates a difficult-but-safe experience from a genuinely dangerous one.

So, is ayahuasca dangerous?

The honest answer is: it depends almost entirely on who is drinking it, what else is in their body, and where they are doing it. In controlled settings with proper screening, large reviews describe ayahuasca as having an "acceptable safety profile," with serious adverse events rarely reported in otherwise-healthy people.^[1] The most common effects, intense nausea and vomiting (often called the purge), are unpleasant but expected and usually mild and transient.

That is the reassuring part. The important caveat is that "controlled setting" and "properly screened" are doing a lot of work in that sentence. Ayahuasca's real dangers are largely predictable, and most of them are avoidable. The brew is pharmacologically active in ways that matter, and the people most likely to be harmed are those with specific risk factors who were never screened out in the first place.

If you read nothing else, read this: ayahuasca is not a casual substance, and the single most important safety decision you make is not "should I do this" but "who will I do this with, and will they take my health history seriously." Our guide to ayahuasca safety and contraindications goes deeper than this overview.

Drug and medication interactions: the biggest hidden risk

This is the danger most newcomers underestimate. Ayahuasca contains beta-carboline alkaloids that act as monoamine oxidase inhibitors (MAOIs).^[2] MAOIs change how your body processes certain neurotransmitters and other drugs, which creates a defined set of interactions that can be serious.

The most important is with serotonergic antidepressants. Combining ayahuasca with SSRIs or SNRIs raises the risk of serotonin syndrome, a potentially life-threatening build-up of serotonin; a documented case involved a patient taking fluoxetine.^[2] Other MAOIs, lithium, stimulants such as amphetamines and MDMA, certain cough medicines containing dextromethorphan, and supplements like St John's wort also feature in the interaction warnings.^[1] Separately, MAOIs interacting with tyramine-rich foods can in theory contribute to a hypertensive crisis, which is part of why retreats ask you to follow a pre-ceremony dieta.

Cardiovascular strain: real but usually modest

Ayahuasca measurably raises blood pressure and heart rate for a period after drinking. Human pharmacology studies have recorded moderate, transient increases, on the order of roughly 10 mmHg in blood pressure, peaking around an hour to ninety minutes in, with smaller and less consistent effects on heart rate.^[3] For most healthy people this is comparable to the strain of moderate exercise and passes.

The concern is for people with existing cardiovascular disease, uncontrolled high blood pressure, or heart-rhythm conditions, for whom that surge is not trivial. Several of the deaths examined in a detailed review involved underlying heart conditions, including heart attacks and one case of Marfan syndrome.^[4] This is exactly why a careful retreat asks detailed cardiac questions and why hiding a heart condition is dangerous. We cover this in ayahuasca and your heart.

Psychiatric risk: who is genuinely vulnerable

Psychologically, the experience can be overwhelming. Acute fear, confusion, and distressing visions are common, and a minority of people find the after-effects difficult enough to seek professional support. In the Global Ayahuasca Survey, around 56% of users reported some mental-health-related adverse effect at some point, though only about 12% sought professional help for it, and most effects were transient.^[5]

The more serious, and rarer, risk is psychosis. A systematic review of human studies found no reports of prolonged psychotic reactions in controlled clinical settings, and estimated the risk of a psychotic episode at well under two per 100,000 sessions. Crucially, the cases that did occur clustered in people with a personal or family history of psychotic disorders.^[6] This is the strongest argument for honest psychiatric screening.

Screening people with a family or personal history of psychotic symptoms and disorders is crucial.

If you have a personal or family history of schizophrenia, bipolar disorder, or psychosis, the risk is meaningfully higher, and most reputable centres will and should decline you. Our piece on whether ayahuasca can trigger psychosis and the wider list of who should not take ayahuasca explain why.

Physical safety: falls, dehydration, and the setting itself

Some dangers have nothing to do with pharmacology and everything to do with being deeply altered for hours. People can fall, wander, or injure themselves if they are not supervised. Vomiting and, in some traditions, purging from both ends can cause dehydration. In the deaths reviewed by researchers, contributing factors included water intoxication (drinking too much, too fast), drowning, and head trauma.^[4] None of these are caused by ayahuasca itself; they are caused by an altered person in an unsafe environment without attentive sober support.

This is the practical case for a well-run retreat where you know what to expect: trained people watching the room, a safe physical space, and water and care managed for you rather than left to your impaired judgement.

Deaths, additives, and what the evidence actually shows

The deaths that make headlines deserve a clear-eyed look, because they are frequently misunderstood. A detailed review of 58 deaths linked to ayahuasca between 2010 and 2022 found that no toxicological or forensic examination has ever determined that ayahuasca caused a death by acute intoxication.^[4] Researchers estimate it would take roughly 20 times a normal psychoactive amount to reach a toxic level, which the brew's taste and emetic effects make practically impossible.^[4]

So what did cause those deaths? The recurring themes are revealing:

• Added plants. Some traditions add potent tobacco preparations or plants like toé (a Brugmansia species containing scopolamine). Four deaths in the review involved tobacco poisoning, and others involved scopolamine-type contamination.^[4]
• Pre-existing conditions that were never screened for, especially cardiac.
• Other drugs in the person's system, including synthetic substances.
• Accidents and lack of supervision in unsafe settings.

In other words, the lethal risk ties directly to additives, poor screening, and the absence of trained facilitators, not to the brew in isolation.

Unregulated settings: the real multiplier of risk

Almost everything above gets worse without regulation. There is no global licensing body for ayahuasca, no guaranteed standard of screening, and no guarantee the person leading your ceremony is trained to recognise a medical or psychiatric emergency. Clinicians note that risk rises sharply as the setting becomes less controlled, with unsupervised use being the most dangerous of all.^[7]

Doing ayahuasca alone or at home, with no screening and no sober support, removes every safeguard discussed here at once. The honest framing is not "the substance is safe" or "the substance is deadly," but "the substance is roughly as safe as the screening, the brew, and the people around you make it."

How to make it meaningfully safer

You cannot remove all risk, but you can stack the odds heavily in your favour:

• Disclose everything. Every medication, supplement, and physical or psychiatric condition, to both your own clinician and the retreat. Concealment is the most dangerous thing you can do.
• Insist on real screening. A centre that does not ask detailed health questions is screening you out of safety, not in.
• Ask what is in the brew and whether additives like tobacco or toé are used.
• Choose supervised, in-person settings with people trained to handle emergencies. Our guide to choosing a retreat safely and the questions to ask a retreat are built for exactly this.
• Treat medical decisions as medical. Anything involving stopping medication belongs with your prescriber, not a forum or a facilitator.

Ayahuasca is a powerful substance with genuine, documented risks. It is also one where most serious harm is predictable and preventable. The danger lives less in the cup than in everything around it. For more background, start with what ayahuasca is, and if you are in distress now, please reach out to local emergency services or, in the UK, the Samaritans on 116 123, and see our resources page.