Ayahuasca, ibogaine and peyote: how three traditional psychedelics differ in chemistry, culture, law and risk

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People often lump these three together as “plant medicines”. Chemically, culturally and legally they have little in common beyond producing powerful altered states. This guide compares them side by side, using peer-reviewed studies and the text of Canadian law. Each factual paragraph ends with an evidence label. For the basics of the brew itself, read what is ayahuasca first.

Ayahuasca vs ibogaine vs peyote: what are the active compounds?

Ayahuasca combines DMT (N,N-dimethyltryptamine, a short-acting psychedelic) with β-carbolines (beta-carbolines), a family of alkaloids that includes harmine, harmaline and tetrahydroharmine. On its own, swallowed DMT is broken down by the enzyme monoamine oxidase (MAO) before it reaches the brain. The β-carbolines inhibit MAO, which in a controlled trial appeared to act mainly in the gut and liver, letting DMT reach the circulation (Riba et al., 2003). Evidence: established.

Ibogaine is a single indole alkaloid, not a brew. Its effects are complicated by its main breakdown product, noribogaine, which is also psychoactive and is longer lived; long-lasting effects are attributed to it (Koenig and Hilber, 2015; Brunt, 2026). Mescaline is a phenethylamine, a different chemical family from DMT and ibogaine, and is the main psychoactive alkaloid of peyote, which also contains other alkaloids (Doesburg-van Kleffens et al., 2023). Evidence: established.

Which receptors do they act on, and how long do effects last?

DMT is a 5-HT2A agonist, meaning it activates the serotonin 2A receptor that classic psychedelics share. In a double-blind, placebo-controlled trial in 18 experienced volunteers, ayahuasca’s subjective effects peaked between 1.5 and 2 hours, and the peak matched the time of highest DMT in the blood (Riba et al., 2003). Doses are not reproduced here. Evidence: established.

Ibogaine is different in kind. Reviews describe it acting at the kappa-opioid receptor (an opioid receptor linked to dysphoria and altered perception), as a blocker of the NMDA glutamate receptor (the target of ketamine), at serotonin and dopamine transporters and at nicotinic receptors (Mitchell and Anderson, 2024; Brunt, 2026). One review notes it has moderate-to-weak affinity for a wide spectrum of targets (Wasko et al., 2018). Evidence: established that it is multi-target; which target drives which effect is preliminary.

Ibogaine’s plasma half-life is about 4 to 7 hours, but heart-rhythm changes after a single intake have lasted several days (Koenig and Hilber, 2015). Mescaline, like DMT, activates 5-HT2A (Doesburg-van Kleffens et al., 2023). In a randomized, double-blind crossover trial in 32 healthy people, mescaline’s effects lasted longest (mean 11.1 hours), against 8.2 for LSD and 4.9 for psilocybin, with no clear difference in the kind of altered state (Ley et al., 2023). Evidence: established for these study conditions.

Where do these traditions come from?

Ayahuasca in the Amazon and beyond

A 2024 review describes ayahuasca as used ceremonially in the Amazon Basin for at least hundreds of years, and widely today in shamanic and religious settings in and beyond South America (Mitchell and Anderson, 2024). How far back drinking goes is debated by historians; our ayahuasca explainer covers that history, and Santo Daime and the UDV covers the Brazilian churches. Evidence: established for current use; its age is unresolved.

Iboga and the Bwiti tradition of Gabon

Iboga, a West African shrub, is central to Bwiti, a spiritual tradition of Gabon and Cameroon. A review describes its use by Bwiti and Mbiri groups for centuries in religious ceremonies (Wasko et al., 2018), and other reviewers describe initiation rituals at the high end of use (Koenig and Hilber, 2015). Ibogaine itself was later sold as a medicine in France before being withdrawn, and from the 1960s it was promoted in the United States as an addiction treatment (Wasko et al., 2018). Evidence: established.

Peyote and the Native American Church

Peyote use spread among Indigenous peoples of North America from the 1870s and is central to the rituals of the Native American Church, founded in 1914, where the cactus is understood as a teacher rather than a drug (Doesburg-van Kleffens et al., 2023). In the United States, federal law states that use, possession or transport of peyote by an Indian for bona fide traditional ceremonial purposes is lawful and cannot be prohibited by the federal government or any state (42 U.S.C. §1996a). Evidence: established.

Are ayahuasca, ibogaine and peyote legal in Canada?

They sit in three different places. Schedule III of the Controlled Drugs and Substances Act lists DMT as item 7, harmaline as item 9 and harmalol as item 10, each with any salt. Harmine, the main β-carboline measured in ayahuasca, is not named in the Act (Justice Laws, CDSA). Because DMT is scheduled, ayahuasca falls under the Act; religious groups have sought section 56 exemptions, covered in our DMT and Canadian law guide. Evidence: established.

Mescaline is Schedule III item 17, worded “and any salt thereof, but not peyote (lophophora)”. Ibogaine is not in the Act at all. Instead, “ibogaine or its salts or derivatives or analogues” has been on Health Canada’s Prescription Drug List since 16 May 2017 (Prescription Drug List), and a search of Health Canada’s Drug Product Database on 20 October 2026 returned no product with ibogaine as an active ingredient (Drug Product Database). The Act we read was current to 30 September 2026 (Justice Laws, CDSA). This is general information, not legal advice. Evidence: established.

What does the research show so far?

Ayahuasca has the deepest clinical record of the three. In a double-blind, placebo-controlled trial in 29 people with treatment-resistant depression, depression scores were lower in the ayahuasca group at days 1, 2 and 7 (Palhano-Fontes et al., 2019). A 2026 review of 26 registered trials of DMT, ayahuasca and DMT combined with harmine found most were phase I safety studies in healthy volunteers (Stojanović et al., 2026). Evidence: preliminary, from one small controlled trial.

Ibogaine evidence comes mostly from case reports, open-label and observational studies, with a few placebo-controlled trials of noribogaine (Brunt, 2026). A 2023 systematic review found some efficacy for substance use disorders but called its cardiotoxicity and mortality worrying (Mosca et al., 2023). Evidence: preliminary.

A Stanford study gave magnesium with ibogaine to 30 veterans with brain injuries and reported large changes on disability, PTSD and depression scales; it had no control group, and the authors say controlled trials are needed (Cherian et al., 2024). A 2026 critique argues the study was methodologically weak and departed from its registration (Gorman, 2026). Evidence: preliminary.

Mescaline research is thinner still. A 2026 systematic review found 66 relevant studies but only 10 suitable for analysis, and called the literature limited and of highly variable quality (Shaw et al., 2026). The best-controlled modern data come from healthy volunteers, not patients (Ley et al., 2023). Evidence: preliminary.

What are the documented risks of each?

For ayahuasca, the largest dataset is the Global Ayahuasca Survey of 10,836 self-selected people. Acute physical effects, mainly vomiting, were reported by 69.9%, and 2.3% reported needing medical attention afterwards. Adverse mental health effects in the following weeks or months were reported by 55.9%, and about 12% sought professional support for them (Bouso et al., 2022). Because the β-carbolines inhibit MAO, interactions with other drugs are a separate concern, covered in our ayahuasca guide. Evidence: preliminary, from a self-selected survey.

Why is ibogaine’s heart risk different?

The QT interval is the stretch of the heartbeat, seen on an electrocardiogram (ECG), in which the ventricles recharge. When a drug prolongs it, the risk rises of torsades de pointes, a chaotic rhythm that can become fatal. Lab studies show ibogaine blocks hERG potassium channels, which carry the current that ends each heartbeat; reviewers propose this as the mechanism for the QT prolongation seen in case reports (Koenig and Hilber, 2015). Evidence: established for the channel block; the clinical link is supported by case reports.

Deaths are documented. A forensic review of every known fatality outside West Central Africa from 1990 to 2008 counted 19 people who died 1.5 to 76 hours after taking ibogaine. Pre-existing illness, mainly cardiovascular, or other substances explained or contributed to 12 of the 14 deaths with adequate post-mortem data (Alper et al., 2012). Evidence: established.

A 2026 review adds that case reports show these events in people without known heart conditions, and that genetic differences in the liver enzyme CYP2D6 may raise risk for some (Brunt, 2026). Evidence: established that deaths and arrhythmias are associated; individual causation is not always clear.

Even under hospital monitoring the effect is large. In a Dutch open-label study of 14 people with opioid use disorder, the QTc (heart-rate corrected QT) rose by 95 milliseconds on average, half the participants passed 500 milliseconds, and in six the prolongation lasted beyond 24 hours. No torsades de pointes occurred, but all had severe transient ataxia, losing the ability to walk unaided (Knuijver et al., 2022). Evidence: preliminary, from one small study.

Mescaline’s profile looks more like other classic psychedelics. In the healthy-volunteer trial, tolerability was comparable to LSD and psilocybin, with slightly more adverse effects 12 to 24 hours later (Ley et al., 2023). Across older and naturalistic reports, raised blood pressure, headache, nausea and vomiting were frequently reported (Shaw et al., 2026). Evidence: preliminary.

Is peyote endangered?

Peyote is listed as Vulnerable on the IUCN Red List and is protected in Mexico, according to a population study by cactus ecologists. They list the main threats in the United States as habitat loss, over-harvesting through the legal trade that supplies the Native American Church, and poaching, while noting that the impacts have never been quantified. Harvested plants take at least 6 to 8 years to regenerate, and up to 10 years to grow from seed to harvestable size (Ermakova et al., 2020). The study is a preprint, not peer reviewed. Evidence: preliminary.

That creates a real tension: the plant at the centre of a protected religious practice grows slowly in a small range, and demand has grown. The same authors call for conservation and restoration involving Native Americans and local landowners (Ermakova et al., 2020). Evidence: preliminary.

What we still don’t know

• Whether ayahuasca’s depression findings hold up in larger, independent controlled trials.
• Which of ibogaine’s many targets produce which effects, and whether its heart risk can be reliably screened out.
• Whether ibogaine’s reported benefits survive placebo-controlled trials; the recent veteran study had no control group.
• How mescaline compares with other psychedelics in patients rather than healthy volunteers.
• How fast wild peyote populations are declining; nobody has measured it.

For how ayahuasca relates to DMT on its own, read ayahuasca vs DMT. For DMT’s chemistry, start with the pillar guide, what is DMT.

Shroomverse sells mushroom products. This article is general information about ayahuasca, ibogaine and peyote. It is not medical, legal or purchasing advice, and it does not recommend any product.