Educational summary · Last reviewed: 2026-05-13 · 6 cited studies. This page is not medical advice. Ayahuasca is not approved for the treatment of any medical condition.
Emphasis word: research
What is DMT?
N,N-dimethyltryptamine (DMT) is a tryptamine alkaloid that occurs naturally in many plants and in trace amounts in the mammalian body. In ayahuasca, DMT is the active psychotropic compound; it is concentrated in the leaves of Psychotria viridis (chacruna), brewed together with the vine Banisteriopsis caapi.
Oral DMT alone is not psychoactive. The enzyme monoamine oxidase A (MAO-A) in the gut and liver rapidly degrades it before it can reach systemic circulation. Ayahuasca solves this through the beta-carboline alkaloids in the vine — harmine, harmaline, and tetrahydroharmine, which reversibly inhibit MAO-A and allow oral DMT to become bioavailable (Riba 2003).
Once systemic, DMT binds primarily to serotonin 2A receptors (5-HT2A) on cortical pyramidal neurons, with additional affinity at 5-HT1A, 5-HT2C, and sigma-1 sites. This receptor profile overlaps with, but is not identical to, psilocin, the active metabolite of psilocybin. The subjective experience is correspondingly related but distinct in time-course and phenomenology.
Plant input
DMT-containing leaves (Psychotria viridis) brewed with the beta-carboline-rich vine (Banisteriopsis caapi).
MAO inhibition
Beta-carbolines (harmine, harmaline, tetrahydroharmine) reversibly inhibit gut MAO-A, preventing first-pass degradation of DMT.
Oral DMT bioavailability
With MAO suppressed, oral DMT becomes systemically available, a route normally inactive without MAOI co-administration.
5-HT2A binding
DMT binds primarily to serotonin 2A receptors on cortical pyramidal neurons; additional affinity at 5-HT1A, 5-HT2C, and sigma-1.
Altered consciousness
Acute perceptual, affective, and cognitive shifts over four to six hours, followed by a post-session integration window.
Ayahuasca in clinical research
Published clinical work on ayahuasca is smaller in scale than the psilocybin literature, but several studies are worth reading directly.
Osório and colleagues (2015) reported a preliminary open-label study in six patients with recurrent depression, finding significant reductions in HAM-D and MADRS scores within hours of a single session, sustained at 21-day follow-up. Sanches and colleagues (2016) extended this in a larger open-label sample (n=17) combining clinical measures with SPECT neuroimaging, reporting reduced depression scores alongside altered regional blood-flow patterns in left nucleus accumbens, right insula, and left subgenual area.
The strongest single piece of evidence comes from Palhano-Fontes and colleagues (2019), a randomized, double-blind, placebo-controlled trial in treatment-resistant depression (n=29). The investigators reported a significant antidepressant effect of a single ayahuasca dose versus placebo at day 1 and at day 7 on the MADRS. This remains the only published placebo-controlled RCT of ayahuasca in treatment-resistant depression to date.
For broader context across psychedelic compounds, dos Santos and colleagues (2016) published a systematic review covering ayahuasca, psilocybin, and LSD trials from the prior twenty-five years. The review catalogs both the signal and the methodological limits, small samples, expectancy effects, short follow-up windows. See /research/methodology for how we read and report on this body of work.
Cited studies
Osório FL, Sanches RF, Macedo LR, et al. (2015).
Antidepressant effects of a single dose of ayahuasca in patients with recurrent depression: a preliminary report. Revista Brasileira de Psiquiatria.
Open-label study (n=6) reporting significant reductions in HAM-D and MADRS scores within hours of a single ayahuasca session, sustained at 21-day follow-up.
Sanches RF, de Lima Osório F, dos Santos RG, et al. (2016).
Antidepressant effects of a single dose of ayahuasca in patients with recurrent depression: a SPECT neuroimaging study. Journal of Clinical Psychopharmacology.
Open-label study (n=17) combining clinical depression measures with SPECT imaging; reported reduced symptoms and altered blood-flow patterns in left nucleus accumbens, right insula, and left subgenual area at day 1 and day 21.
Palhano-Fontes F, Barreto D, Onias H, et al. (2019).
Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial. Psychological Medicine.
Randomized, double-blind, placebo-controlled trial in treatment-resistant depression (n=29). Reported significant antidepressant effect of a single ayahuasca dose versus placebo at day 1 and day 7 on MADRS.
Morales-García JA, Calleja-Conde J, Lopez-Moreno JA, et al. (2020).
N,N-dimethyltryptamine compound found in the hallucinogenic tea ayahuasca, regulates adult neurogenesis in vitro and in vivo. Translational Psychiatry.
Preclinical study reporting that DMT promotes neurogenesis in adult mouse hippocampus and improves performance on memory tasks, supporting a neuroplasticity-linked mechanism.
dos Santos RG, Osório FL, Crippa JAS, et al. (2016).
Antidepressive, anxiolytic, and antiaddictive effects of ayahuasca, psilocybin and lysergic acid diethylamide (LSD): a systematic review of clinical trials published in the last 25 years. Therapeutic Advances in Psychopharmacology.
Systematic review across ayahuasca, psilocybin, and LSD clinical trials. Catalogs the strength and limits of the evidence base across depression, anxiety, and substance-use contexts.
Riba J, Valle M, Urbano G, et al. (2003).
Human pharmacology of ayahuasca: subjective and cardiovascular effects, monoamine metabolite excretion, and pharmacokinetics. Journal of Pharmacology and Experimental Therapeutics.
Controlled pharmacokinetic study characterizing the time-course of oral DMT bioavailability in the presence of beta-carboline MAO inhibitors, plus cardiovascular and subjective profile.
The ceremonial arc: preparation, ceremony, integration
Functional neuroimaging studies after classic psychedelic sessions consistently report acute disintegration of the default mode network (DMN), the set of brain regions most active during self-referential thought and rumination — followed by altered functional connectivity in the days that follow. The clinical work above is best understood inside a three-phase arc: preparation, ceremony, integration. The ceremony is one input; the weeks framing it are where the change is consolidated or lost.
Preparation
Dietary restrictions, intention setting, medical and psychological screening, taper of contraindicated medications.
Ceremony
Acute disintegration of default mode network connectivity; expanded between-network communication during the experience.
Integration
Post-session window of altered DMN re-formation; structured reflection, somatic work, and behavioral re-engagement.
Neuroplasticity: a mechanistic candidate for durability
One leading hypothesis for the durability of post-session change is experience-dependent plasticity. Morales-García and colleagues (2020) reported in vivo evidence that DMT promotes adult neurogenesis in mouse hippocampus and improves performance on memory-related tasks. Earlier preclinical work on classic psychedelics broadly has shown rapid increases in dendritic spine density and BDNF signaling. The hypothesis is not that the molecule heals, but that it temporarily raises plasticity, and integration chooses what grows in that window. See /science/neuroplasticity for how Ceremonia structures the integration period.
Shamanic context: thousands of years before the lab
Ayahuasca is not new. Indigenous Amazonian traditions have worked with the brew ceremonially for generations long preceding the Western research literature. Contemporary religious and ceremonial use in the United States operates under the Religious Freedom Restoration Act framework, with specific federal exemptions for established sacramental traditions. This page treats the published research as one lens among several, not the only or even the primary one — on a sacrament that has been understood and held by other lineages for far longer.
Safety considerations
Because the beta-carbolines in ayahuasca are reversible MAO-A inhibitors, ayahuasca interacts with a wide range of medications and dietary compounds. The most important categories to flag with a screening clinician:
- SSRIs and SNRIs: concurrent use with an MAO inhibitor carries serotonin syndrome risk. A physician-supervised taper is the baseline expectation before any ceremonial work.
- Tyramine-containing foods: aged cheeses, cured meats, fermented soy, and certain alcoholic beverages can trigger hypertensive responses when MAO is inhibited. A pre-ceremony diet is part of standard preparation.
- Other psychiatric medications and stimulants: a comprehensive medication review is mandatory; the intake at /journeys/heal includes screening for both absolute and relative contraindications.
- Personal or family history of psychosis: treated as a screening exclusion in published trials and in ceremonial screening protocols.