The basics
What ayahuasca is and how it works
Ayahuasca is a brew made from two plants: the Banisteriopsis caapi vine and the leaves of Psychotria viridis. Neither plant produces significant psychedelic effects on its own — the combination is what matters.
The P. viridis leaves contain DMT — a potent psychedelic that is normally broken down by digestive enzymes before reaching the brain. The B. caapi vine contains harmala alkaloids (harmine, harmaline, tetrahydroharmine) which act as reversible MAO inhibitors, blocking those enzymes and allowing DMT to enter the bloodstream. The result is a 4–6 hour experience of unusual depth and intensity.
The brew has been used by Amazonian indigenous peoples — particularly Shipibo, Shuar, and many other groups — for at least 2,500 years. It is embedded in complex healing traditions involving trained healers (curanderos) who work with the medicine through icaros — healing songs said to guide and shape the experience.
Active compounds
DMT from P. viridis — acts on 5-HT2A serotonin receptors
Harmala alkaloids from B. caapi — reversible MAO inhibition enabling oral DMT activity
Duration & onset
Onset: 20–60 minutes
Peak: 1–3 hours
Total: 4–6 hours
Aftereffects: mild for 24–48 hrs
Legal status
Legal: Peru, Costa Rica, Brazil
Legal gray: Netherlands (tea form)
Schedule I: United States, Canada, most of Europe
Addiction potential
Ayahuasca is not considered addictive — no withdrawal syndrome observed. It has demonstrated anti-addictive properties for alcohol, cocaine, and other substances in multiple studies.
Unlike psilocybin or LSD, ayahuasca experiences are highly physical. Nausea and vomiting are common — referred to as la purga (the purge) and considered a normal, even beneficial part of the process in indigenous tradition. The experience is often described as deeply emotional, visionary, and confrontational — bringing suppressed material to the surface with unusual clarity.
What the science shows
Evidence for therapeutic use
Ayahuasca research is less developed than psilocybin or MDMA but growing rapidly. The largest study to date — a Global Ayahuasca Survey of 7,576 participants across 50 countries — found significant associations between ayahuasca use and improved psychological health, reduced distress, and enhanced emotional resilience.
✓ Randomized controlled trial
Treatment-resistant depression
A placebo-controlled trial found significant rapid antidepressant effects from a single ayahuasca session in people with treatment-resistant depression. Effects were observable within hours and maintained at one-week follow-up. The harmine alkaloids in ayahuasca appear to stimulate neurogenesis — growth of new neural cells — which may underpin the antidepressant effect.
Palhano-Fontes et al. (2019). Rapid antidepressant effects of the psychedelic ayahuasca. Psychological Medicine.
✓ Systematic review
Addiction and substance use
A 2024 systematic review found antidepressant, anti-addictive, and anti-anxiety effects associated with ayahuasca. The harmine component specifically has shown reduced recidivism to alcohol, cocaine, and methamphetamine in research. A naturalistic study in Canada found reduced problematic alcohol and drug use at 12 months in people who had attended ayahuasca retreat programs.
Sheth et al. (2024). Effects of Ayahuasca on Psychological Disorders. Cureus.
✓ Large naturalistic survey
General wellbeing & mental health
The Global Ayahuasca Survey — 7,576 participants, 50 countries — found frequent ayahuasca use correlated with better psychological health, reduced distress, and enhanced emotional resilience. Around 75% of participants reported sustained emotional and psychological benefits months after ceremony.
Journal of Psychoactive Drugs (2024).
◑ Emerging
PTSD and trauma
PTSD-specific RCTs are still emerging, but the 2024 systematic review found ayahuasca improved quality of life and showed promise for PTSD. Anecdotal reports from veteran-focused programs are compelling, and the mechanism — emotional processing with reduced fear response — is theoretically well-suited to trauma.
Sheth et al. (2024) & Global Ayahuasca Survey (2024).
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How it may work: DMT activates 5-HT2A serotonin receptors, creating a window of neuroplasticity. The harmine alkaloids independently promote neurogenesis. Together, they appear to allow traumatic memories to be reprocessed in a state of reduced defensive reactivity — the same mechanism proposed for other psychedelics. The visionary quality of the experience is thought to contribute to outcomes, not merely accompany them.
What to expect
The ceremony hour by hour
Ceremonies are held at night in a designated space called a maloka — a large traditional hut or prepared ceremonial room. They run from approximately 8pm through to 2–4am. Each person is given a mattress, pillow, blanket, and bucket.
Preparation & intention setting
Healers introduce the ceremony, explain the process, and answer questions. Participants share names and intentions. The space is blessed and prepared. This grounding period establishes the psychological set that will shape the experience.
The brew is served
Participants approach the healer individually to receive a small cup of the brew — bitter, dark, and earthy. First ceremonies typically receive a smaller dose. Hold your intention before drinking. You return to your mat and wait. The space is kept dark or dimly lit.
Onset — the medicine arrives
Heaviness or warmth in the stomach. Possible nausea. Subtle visual changes — colors sharpen, geometric patterns appear behind closed eyes. Anxiety is common at this stage. Don't fight it. Slow breathing helps. The medicine is beginning its work.
Peak — the journey unfolds
Vivid visions, intense emotional material, profound insights, or difficult confrontations with suppressed content. The healer sings icaros — healing songs — which many describe as guiding the experience. Physical purging is common and considered cleansing. Stay on your mat, keep eyes closed, surrender to what arises.
Descent and return
The intensity gradually subsides. Clarity returns. Many describe this as the most important phase — processing what arose. The space remains open and facilitated. You may receive an additional smaller dose to deepen or clarify material.
Integration circle
Reputable programs hold a group sharing circle the morning after ceremony. Participants share what arose. Facilitators help contextualise and ground the experience. This is where much of the therapeutic value is consolidated. Rest and gentle activities fill the remainder of the day.
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The most important instruction: Surrender. The most difficult experiences during ceremony typically come from resistance — trying to control, analyze, or escape what's arising. Breathe, stay with it, trust that it will pass. Fighting prolongs and intensifies difficulty. Surrendering allows it to move through.
Physical preparation
The dieta — what to eat and avoid
The traditional dieta is not just a food restriction — it is a physical and spiritual preparation beginning 2–4 weeks before ceremony. The dietary restrictions serve real pharmacological purpose: because ayahuasca contains MAO inhibitors, certain foods create dangerous interactions.
❌ Avoid for 2–4 weeks before
- Alcohol (all forms)
- Pork and aged/cured meats
- Aged cheeses and fermented foods
- Overripe or dried fruits
- Soy sauce, miso, sauerkraut, kimchi
- All recreational drugs including cannabis
- Highly processed or spicy foods
- Caffeine (reduce or eliminate)
- Contraindicated medications (see below)
✓ Eat freely
- Fresh vegetables and leafy greens
- Fresh fruits (not overripe)
- Grains: rice, oats, quinoa
- Legumes: lentils, chickpeas, beans
- Fresh fish and chicken (plain)
- Nuts and seeds (unsalted)
- Herbal teas (non-stimulant)
- Plenty of water
- Mild, clean, lightly seasoned foods
The tyramine restriction is pharmacologically critical. MAO inhibitors prevent the breakdown of tyramine in the body. High-tyramine foods — aged cheeses, fermented foods, cured meats — can cause tyramine to accumulate to dangerous levels, potentially resulting in hypertensive crisis. This is the same reason people taking pharmaceutical MAOIs receive strict dietary restrictions.
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On the day of ceremony: Eat lightly or not at all for 4–6 hours before the ceremony. A heavy stomach increases nausea. Stay well hydrated during the day but don't drink large amounts immediately before — this can trigger uncomfortable vomiting during the experience.
Critical safety information
Drug interactions — the most important section
Because ayahuasca contains MAO inhibitors, it has more significant drug interactions than most other psychedelics. Some combinations are potentially life-threatening. This is not an area to take casually.
| Drug / substance | Risk | What can happen | Guidance |
|---|
| SSRIs (Prozac, Zoloft, Lexapro, etc.) | ❌ Serious | Serotonin syndrome — potentially life-threatening. Agitation, hyperthermia, rapid heart rate, muscle rigidity, seizures. | Must taper off under medical supervision. Fluoxetine (Prozac) has a 5-week washout period. |
| SNRIs (Effexor, Cymbalta) | ❌ Serious | Same serotonin syndrome risk as SSRIs. Dual mechanism increases risk. | Medical supervision required for tapering. Minimum 2-week washout. |
| MAOIs (pharmaceutical — Nardil, Parnate) | ❌ Contraindicated | Additive MAOI effect — unpredictable potentiation of both tyramine reactions and serotonin effects. | Do not combine under any circumstances. |
| Tricyclic antidepressants (Elavil, Pamelor) | ❌ Serious | Serotonin syndrome risk. Serotonergic and adrenergic activity interacts with ayahuasca's MAOI properties. | Medical supervision required for tapering. |
| Tramadol | ❌ Serious | Serotonin syndrome risk — tramadol inhibits serotonin reuptake in addition to opioid activity. | Do not use within 2 weeks before ceremony. |
| Lithium | ❌ Serious | Increased seizure risk when combined with classic psychedelics including ayahuasca. | Contraindicated. Do not combine. |
| Stimulants (Adderall, Ritalin, cocaine) | ⚠ Caution | Increased cardiovascular stress. Monoamine accumulation with MAOI presence. | Avoid recreational stimulants. Discuss prescription stimulants with doctor. |
| Cannabis | ⚠ Caution | Can intensify and unpredictably alter the experience. May trigger anxiety or paranoia. | Avoid for 2–4 weeks before ceremony. |
| Blood pressure medications | Discuss | Ayahuasca can moderately increase blood pressure. Interaction with antihypertensives is variable. | Disclose to retreat medical team. |
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Never taper psychiatric medications without medical supervision. Stopping SSRIs, SNRIs, or other psychiatric medications abruptly can cause serious withdrawal symptoms. Work with a prescribing physician who understands psychedelic medicine interactions. A responsible retreat will ask about all medications during screening and flag concerns well before you travel.
Who should be cautious
Contraindications and risk factors
Ayahuasca is not appropriate for everyone. These contraindications reflect real mechanisms by which the experience can cause harm.
❌ Absolute contraindications
• Personal/family history of psychosis, schizophrenia, or bipolar I
• Currently on contraindicated medications (without tapering)
• Severe heart conditions or uncontrolled high blood pressure
• Severe liver disease (ayahuasca is metabolized hepatically)
• Active suicidal ideation
⚠ Requires careful screening
• Borderline personality disorder
• Severe dissociative history
• History of psychotic episodes (even brief)
• Pregnancy or breastfeeding
• Eating disorders (severe)
• Age under 18
• Epilepsy or seizure history
• Cardiovascular disease
If you fall into the caution category, that doesn't mean ayahuasca is absolutely off-limits — it means you need a retreat program with rigorous medical screening including a one-on-one intake consultation. The quality of the screening process is one of the clearest indicators of a reputable center.
Making the decision
How to choose a safe retreat
Quality varies enormously in the ayahuasca retreat world — from rigorously run, medically supervised programs to poorly managed operations that create unnecessary risk. These are the things that actually matter.
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Medical screening before acceptance. A reputable center will ask about your full medical history, current medications, and psychiatric background before confirming your spot. If the application is a brief form with no follow-up call, that's a warning sign.
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Experienced, verifiable healers with clear lineage. Ask about the healer's training, tradition, and how long they've been working with the medicine. Working with a family who harvests their own medicine — common among Shipibo lineages — is a positive sign.
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Preparation and integration included, not optional. The ceremony is only part of the work. Programs that include pre-retreat preparation calls and post-retreat integration circles are meaningfully safer and produce better outcomes. These should be built in, not sold as add-ons.
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Reasonable group size with adequate facilitators. More than 15–20 participants per ceremony with only one or two facilitators is a red flag. You need support available to you specifically, not just available somewhere in the room.
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Transparent about what's in the brew. Some shamans add additional plants — mapacho tobacco, toé (brugmansia), or others. These additions change the experience and risk profile significantly. Ask specifically what the brew contains. Be cautious about vague answers.
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References from past participants available on request. Any reputable program can connect you with alumni willing to share their experience. A center that hesitates at this request has something to hide.
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Walk away from: Programs that promise specific outcomes ("guaranteed healing"), dismiss psychiatric history, skip medication screening, don't discuss the dieta seriously, or have reports of facilitators crossing physical or sexual boundaries with participants. These are not rare — they happen, and they are preventable by choosing carefully.
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Peru vs. Costa Rica: Peru (Iquitos, Sacred Valley) offers the most traditional and culturally rooted experience — jungle settings, Shipibo healers, genuine dieta immersion. Costa Rica offers a more Western-friendly version with luxury amenities, often with authentic Shipibo healers in reputable programs. For ayahuasca specifically, both are excellent destinations with different tradeoffs. See our
retreat directory for vetted centers in both countries.
The work after the work
Integration — why it matters more than the ceremony
Practitioners consistently say the same thing: the ceremony opens a door. Integration is what you do with what you find there. Research suggests structured integration practices can improve long-term outcomes for the majority of participants.
The weeks following an ayahuasca retreat are a period of unusual openness and sensitivity. Insights that feel crystal clear during ceremony can fade without deliberate anchoring. Difficult material that surfaced needs time — often professional support — to be metabolized into lasting change. This is not a passive process.
Core integration practices
Journaling daily for at least 2–3 weeks after the retreat. Don't try to interpret everything immediately — write down what arose, what you saw, what you felt. Meaning often clarifies over weeks, not days.
Working with an integration therapist or coach — someone trained in psychedelic integration who can help you process difficult material without pathologizing the experience. Our integration coach directory has vetted practitioners who understand plant medicine work specifically.
Community — talking with others who have worked with plant medicine, through your retreat's alumni network, online communities, or local integration circles, provides context and normalizes the process of incorporating insights into daily life.
Lifestyle anchoring — the insights from ceremony almost always point toward specific changes: in relationships, work, habits, or ways of seeing. The integration period is the time to begin those changes deliberately and concretely, not to wait for them to happen on their own.
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How long does integration take? Many practitioners describe a six-month to one-year integration window for a meaningful ayahuasca retreat. Some material continues to unfold for years. This is one reason experienced practitioners caution against repeating ceremony too frequently — give the work time to settle before going back.
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