A stethoscope lying on a dark wooden table

Medications and health conditions: who shouldn’t sit

BySafe Ceremonies

Some people should not take part in certain ceremonies, at least not yet and not without medical advice. That isn’t a judgment about their readiness or their spiritual life. It’s about chemistry: a few common medicines interact dangerously with substances used in ceremonies, and a few health conditions make those substances riskier.

This guide summarises what published research says about the main risks. It is not medical advice, and it can’t cover every medicine or every condition. Use it to have a better-informed conversation with your doctor or prescriber, and to judge whether a center’s screening is any good.

One rule before anything else

Don’t stop or change a prescribed medicine because a retreat told you to. That decision belongs to you and the person who prescribed it.

Stopping some medicines suddenly is risky in itself. The NHS advises never to stop an antidepressant suddenly or without talking to a doctor first. It lists withdrawal symptoms including dizziness, a racing heart, anxiety, low mood and “brain zaps,” and says a doctor will usually help reduce the dose gradually over several weeks or months. For some people withdrawal symptoms can be severe and last for months.

Many retreats ask people to stop medicines first. A 2026 study in JAMA Network Open interviewed 49 organizations advertising psychedelic retreats and found that most of them required or recommended stopping medicines beforehand, for periods ranging from one day to more than six weeks. The researchers warned that this practice may itself add medical and psychological risk, because stopping antidepressants abruptly carries known withdrawal risks and the possibility of relapse.

If a center’s rules and your prescriber’s advice conflict, your prescriber’s advice wins. If that means you can’t attend, the center was right to have a rule, and the right answer is to wait.

Antidepressants

Antidepressants come up more than any other medicine, and the risks differ depending on the ceremony.

With ayahuasca

Ayahuasca brews contain harmala alkaloids, which block monoamine oxidase, an enzyme that breaks down serotonin. In 1998 researchers warned that combining ayahuasca with SSRI antidepressants could cause serotonin syndrome, a dangerous excess of serotonin, with potentially grave results. A center serving ayahuasca should ask about every medicine you take and explain its rules in writing.

With psilocybin

With psilocybin the best-documented effect is different. In a 2023 Johns Hopkins survey, people who took psilocybin mushrooms while on an SSRI reported weaker-than-expected effects about half the time. The dampening sometimes seemed to last for up to three months after stopping. That is a reason people may be tempted to stop their medicine before a ceremony, and a reason to have that conversation with a prescriber well in advance instead.

Lithium

Lithium is one of the clearest warnings in the research. A 2021 analysis of online experience reports found that 47% of 62 reports of a classic psychedelic, such as psilocybin or LSD, taken with lithium described seizures, and 39% involved medical attention. None of 34 reports involving lamotrigine, another mood stabilizer, described a seizure. Reports posted online aren’t a controlled study, and the authors called their conclusion provisional, but the pattern was strong enough that they warned of a significant seizure risk.

Oregon’s licensed psilocybin program doesn’t allow anyone who has taken lithium in the last 30 days to take part.

Bipolar disorder, psychosis and family history

Clinical studies of psychedelics have usually excluded people with bipolar disorder or a psychotic disorder, and people with a parent, sibling or other close relative who has one. The Johns Hopkins safety guidelines published in 2008 describe these exclusions. Oregon’s program bars anyone who has been diagnosed with or treated for active psychosis.

The research behind this caution is still developing:

  • In an international survey of 541 people with bipolar disorder who had used psilocybin mushrooms, about a third described new or worsening symptoms afterwards, most often mania, trouble sleeping and anxiety. Many also reported benefits, and the authors called for careful monitoring in any future trials.
  • A 2024 study of more than 16,000 Swedish twins, looking at symptoms at age 15, found that psychedelic use interacted with genetic vulnerability to schizophrenia or bipolar I disorder in predicting manic symptoms. The authors asked for their findings to be read with caution.

If you have one of these conditions, or a close relative does, tell the center and your doctor. A careful center will ask about family history even if you don’t raise it.

Heart conditions and blood pressure

Classic psychedelics raise heart rate and blood pressure moderately. In the Johns Hopkins guidelines, volunteers whose resting blood pressure was above 140/90 were excluded, and everyone had an ECG first.

Some ceremonial substances put more strain on the heart:

  • Ibogaine can prolong the QT interval, part of the heart’s electrical cycle. A 2015 review counted 19 deaths linked in time to ibogaine between 1990 and 2008, with more since, and concluded that the danger comes from ibogaine combined with other risk factors, such as existing heart disease or other substances that affect heart rhythm, including alcohol, cocaine and methadone. The authors said ibogaine should only be given under strict medical observation with continuous heart monitoring.
  • Kambo can cause a racing heart and swings in blood pressure. A 2025 systematic review found only a few deaths described in the medical literature, including sudden cardiac death, and noted that pre-existing risk factors may make such events worse.

If you have a heart condition, high blood pressure, or symptoms that have never been checked, such as fainting or palpitations, see a doctor before you consider these ceremonies.

Kambo and water

Kambo sessions often involve drinking large amounts of water. Case reports describe people whose blood sodium fell to dangerous levels afterwards. In one, a woman drank 6 litres of water after a session and developed vomiting, confusion and a seizure. In another, published in 2025, a 35-year-old woman died after severe brain swelling; the authors linked it to excess water, sodium loss from vomiting and a suspected effect of the kambo peptides on the hormone that controls water balance. Headache, repeated vomiting and confusion after kambo need urgent medical attention.

Bufo and 5-MeO-DMT with other substances

5-MeO-DMT, the main psychedelic compound in bufo ceremonies, is broken down by the same enzyme that ayahuasca blocks. A 2022 review of research on 5-MeO-DMT describes a 17-year-old hospitalized with extreme agitation, overheating and muscle breakdown after taking it with harmaline, and a death after ayahuasca and 5-MeO-DMT were taken together. The same review found almost no laboratory research in humans.

Some retreats offer several substances over a few days. Ask how they’re separated and screened, and treat any place that offers 5-MeO-DMT close to ayahuasca as one to question closely.

Pregnancy and breastfeeding

Research studies have generally excluded people who are pregnant. Oregon’s rules require facilitators to tell clients who are pregnant or breastfeeding that the risks of psilocybin are unknown. The same uncertainty applies to other ceremonial substances, and kambo and ayahuasca both bring on vomiting. Talk to your midwife or doctor, and expect a careful center to suggest you wait.

Other things to tell the center

Bring a full list to your screening and your doctor’s appointment. Include:

  • Every prescription medicine, with the dose.
  • Medicines you take now and then, for migraine, sleep, allergies or pain.
  • Supplements and herbal products.
  • Alcohol and recreational drugs, including in the weeks before the ceremony.
  • Any history of seizures, fainting, heart trouble or high blood pressure.
  • Any past bad reaction to a psychedelic.

Oregon’s client information form asks about prescription and non-prescription medicines and supplements, and directs facilitators to encourage clients to check with a pharmacist or health care provider about contraindications. A pharmacist can be a quick, practical person to ask.

How to raise it with your doctor

You don’t need your doctor’s blessing to ask a question. Be specific: name the substance, the dates and the medicines you take, and ask what the risks are and what they’d recommend. If they advise against it, ask why, and whether anything would change their view. If you’re nervous about raising it, a written list of questions helps.

If a center has told you to stop a medicine, ask your prescriber directly whether that’s safe, how it should be done and how long it would take. Get the center’s rule in writing first so you can show it to them.

Gentler options

Being ruled out of one ceremony doesn’t rule you out of everything. Practices such as meditation, sound baths, yoga or integration circles carry different risks, and some people come back to plant medicine later, once their health or medicines have changed. Breathwork has its own health questions, so ask about those too.

If you’re in crisis now, please reach out today. In the US, the 988 Suicide & Crisis Lifeline answers calls and texts at 988. Fireside Project’s free psychedelic peer support line, 62-FIRESIDE (623-473-7433), takes calls and texts from 11 a.m. to 11 p.m. Pacific time every day. In an emergency, call your local emergency number.

More guides

A center’s reviews can show you how it handles medicines in practice: whether it called to go over a prescription, or waved it away. You can search the Safe Ceremonies listings and read past participants’ accounts, in categories such as ayahuasca, psychedelic-assisted therapy and kambo.

Sources

Photo: Stethoscope No.120 by Tama998, CC0 1.0.

Safe Ceremonies
Author: Safe Ceremonies

User reviewed ceremonies

Similar Posts