Anadenanthera peregrina

Traditional and historical use

Anadenanthera peregrina seeds have been used as psychoactive snuff — cohoba, yopo, jopo, or paricá — across the Caribbean and northern South America for well over a thousand years. The first European account dates to 1496, when Friar Ramón Pané documented the Taíno of Hispaniola inhaling cohoba through Y-shaped tubes during healing and divination ceremonies.^[2] A ritual bundle from Bolivia dated to around 1,000 CE contained bufotenine, DMT, and harmine together — the oldest biochemical confirmation of combined yopo and ayahuasca-like use in the Americas.^[3]

Western discovery and research

Western scientific interest began when Richard Spruce collected seeds at Rio Negro in 1854; Holmstedt and Lindgren first identified 5-MeO-DMT and DMT in the seeds in 1967,^[8] and the definitive 1977 Schultes monograph documented bufotenine concentrations up to 7.5% of dry seed weight.^[9] Traditional preparation — toasting seeds, grinding to powder, mixing with alkaline ash, and insufflating — remained unchanged across these centuries.^[10][4] Torres and Repke's 2006 ethnobotanical synthesis consolidated the archaeological and chemical record.^[11]

Modern era

DMT was listed as Schedule I under the UN Convention on Psychotropic Substances in 1971; bufotenine and 5-MeO-DMT were not internationally listed.^[12] In the United States, bufotenine was separately placed on Schedule I (DEA code 7433); in the United Kingdom, bufotenine and DMT became Class A under the Misuse of Drugs Act 1971. No clinical trials for yopo or bufotenine have been registered.

Anadenanthera peregrina belongs to the family Fabaceae — the legume family. Linnaeus first described it as Mimosa peregrina in 1753; it passed through Acacia and Piptadenia before Spegazzini established the current binomial in 1923.^[14] A closely related species, Anadenanthera colubrina (cebil, vilca), shares similar alkaloid chemistry and traditional use across southern South America.

The tree is native to the Caribbean islands, the Orinoco basin, and the tropical savannas and dry forests of northern South America — from Colombia and Venezuela through Brazil. It grows in open woodland and disturbed forest margins from sea level to roughly 1,000 meters. It is not commercially cultivated but persists in wild and semi-managed populations across its native range.

A. peregrina reaches 15–25 meters in height, with dark, rough bark often covered in conical spines. Leaves are finely compound, resembling those of other mimosoid legumes. The tree produces small spherical clusters of white or pale yellow flowers and flat, dark brown seed pods containing 3–10 glossy, lens-shaped seeds about 1–2 cm across — the only plant part used for psychoactive preparation. Bark, leaves, and roots do not contain psychoactive concentrations of the relevant alkaloids.

Bufotenine (5-hydroxy-N,N-dimethyltryptamine) is the dominant psychoactive alkaloid in A. peregrina seeds, present at the highest natural concentration of any documented plant source — up to 7.5% of seed dry weight in Venezuelan specimens.^[9] It acts on serotonin receptors through the same pathway as psilocybin and DMT,^[1] producing the intense visual and cognitive disruption characteristic of the yopo experience.

The seeds also contain two secondary tryptamines: DMT (N,N-dimethyltryptamine) and 5-MeO-DMT (5-methoxy-N,N-dimethyltryptamine). 5-MeO-DMT acts on a different serotonin pathway from bufotenine, adding an anxiolytic and dissociative dimension to the experience.^[15] DMT engages multiple serotonin and other receptor systems simultaneously.^[16] All three alkaloids converge downstream on the same cellular signaling cascade that mediates psychedelic effects.^[17]

The ratio of bufotenine to DMT to 5-MeO-DMT varies substantially with seed maturity, geographic origin, and storage duration.^[9] A batch dominated by bufotenine produces a different experience from one with more 5-MeO-DMT. CYP2D6, a liver enzyme, converts 5-MeO-DMT into bufotenine in the body — individuals with slow-metabolizer genetics show dramatically lower conversion rates.^[7] MAO-A is the primary enzyme that clears all three alkaloids.^[18]

Where it acts

Bufotenine activates 5-HT₂A and 5-HT₂C serotonin receptors in the brain's cortex — the same primary targets as psilocybin and LSD.^[1][19] Early researchers doubted bufotenine could even reach the brain; animal studies settled this, showing it accumulates in brain tissue and produces central psychedelic effects.^[20] The secondary alkaloids extend the pharmacological reach — 5-MeO-DMT acts on a different serotonin pathway,^[15] and DMT activates multiple serotonin systems simultaneously.^[16]

What it changes

Bufotenine dampens serotonin's excitatory effects on brainstem neurons — a mechanism shared with LSD.^[21] MAO-A breaks down all three seed alkaloids; blocking that enzyme — whether with pharmaceutical MAOIs or with Banisteriopsis caapi, which contains harmine and harmaline — raises bufotenine exposure up to 9.9-fold.^[22][7]

Onset: 1–5 minutes.^[4] Duration: 20–60 minutes. Nausea and vomiting are near-universal at psychoactive doses. This is the traditional and most widely documented preparation.

The resulting experience is longer, more intense, and carries substantially greater serotonin syndrome risk. This combination is classified as severe for drug interaction purposes.

Per-preparation dose tiers, timelines, and bioavailability data are in the Dose · by preparation card on this page.

Cardiovascular effects are clinically significant at psychoactive doses: tachycardia, hypertension, intense vasoconstriction, facial purpling, chest heaviness, and respiratory stimulation have been documented in historical human administration studies.safety citation needed Nausea and vomiting are near-universal, triggered by serotonin receptor activation in the gut.^[5]

No published studies examine contaminant profiles — pesticides, heavy metals, mycotoxins, or microbial load — in commercially sold seeds or prepared snuff. Alkaloid concentrations vary substantially by provenance, and no standardized testing requirement exists for this market.

Persistent visual disturbances after the experience ends (HPPD) are a documented risk of serotonergic psychedelic use; yopo-specific risk has not been studied but is extrapolated from LSD and psilocybin data.^[23]

SSRIs and SNRIs add serotonergic load, raising the risk of a dangerous overheating and seizure response. Chronic SSRI use also downregulates the serotonin receptor bufotenine targets, potentially blunting effects in unpredictable ways. Severity: moderate to severe.^[24]

CYP2D6 inhibitors (fluoxetine, paroxetine, bupropion) reduce the conversion of 5-MeO-DMT into bufotenine, altering alkaloid exposure unpredictably. Severity: moderate.^[7][24]

Additional serotonergic agents — triptans, tramadol, fentanyl, linezolid — carry additive serotonin syndrome risk.^[24]

All severity classifications are based on animal data and pharmacodynamic class effects. No clinical case report of serotonin syndrome from yopo combined with any pharmaceutical has been published.

Contraindications

A. peregrina occupies a legal gray area in most countries: the plant and seeds are not controlled under international treaty, but the alkaloids they contain are scheduled in most Western legal frameworks. Under the UN Convention on Psychotropic Substances (1971), DMT is Schedule I; bufotenine and 5-MeO-DMT are not internationally listed.^[12] In the United States, bufotenine (DEA code 7433), DMT, and 5-MeO-DMT are all federally Schedule I — the seeds themselves are not listed, but possession with intent to extract alkaloids may trigger structural analog provisions. In the United Kingdom, bufotenine and DMT are Class A, carrying maximum penalties of 7 years for possession and life for supply. In Australia, all three alkaloids are Schedule 9 (Prohibited Substance). Venezuela constitutionally protects indigenous ceremonial use; Brazil and Colombia do not specifically control the seeds, though their scheduled alkaloids remain restricted.citation needed Across the European Union, member state laws vary — bufotenine and DMT are generally controlled under national psychotropic substance laws, with no EU-wide harmonized scheduling of the plant. Legality depends on the specific national framework, the form of possession (seeds versus extracted alkaloids), and prosecutorial intent.