Ayahuasca is a drink made from at least two Amazonian plants: the vine Banisteriopsis caapi, which contains harmala alkaloids, and a plant that contains DMT, most often the leaves of Psychotria viridis. The International Narcotics Control Board describes it in the same terms, as “a preparation made from plants indigenous to the Amazon basin of South America, mainly a jungle vine (Banisteriopsis caapi) and another tryptamine-rich plant (Psychotria viridis)” (INCB Annual Report 2010, §285).
The word comes from Quechua: aya refers to spirits or the dead, waska to a vine or rope. The same drink is called yagé in parts of Colombia and Ecuador and caapi in parts of Brazil. Recipes differ by region and by the person preparing it, which matters for everything else on this site.
The two plants and what each contributes
| Plant | Part used | Main alkaloids | Role in the brew |
|---|---|---|---|
| Banisteriopsis caapi (the vine) | stem and bark | harmine, harmaline, tetrahydroharmine | inhibits the enzyme MAO-A |
| Psychotria viridis (chacruna) | leaves | DMT | the main psychedelic compound |
| Diplopterys cabrerana (chaliponga) | leaves | DMT | used instead of chacruna in some areas |
Other plants are sometimes added, depending on local practice. Tobacco is one of them, and toxicologists have linked at least one death in the literature to nicotine poisoning from such an addition (Brito-da-Costa et al., 2020). A person drinking a cup in a ceremony usually has no way to check what went into it.
Why the combination works
DMT taken by mouth on its own has little effect. The enzyme monoamine oxidase A (MAO-A) in the gut and liver breaks it down before it reaches the brain. Harmine and harmaline from the vine are potent, reversible inhibitors of MAO-A. They hold the enzyme back long enough for DMT to enter the bloodstream, where it acts mainly on serotonin 5-HT2A receptors (Brito-da-Costa et al., 2020).
That mechanism has a direct safety consequence. MAO-A also breaks down serotonin and several medicines. While it is inhibited, drugs that raise serotonin can build up to dangerous levels. The review cited above states that ayahuasca therefore carries a higher risk of drug interactions than other psychedelics. The safety chapter goes through the combinations that matter.
Strength is not standard
There is no standard ayahuasca. One review lists analysed brews with total alkaloid contents ranging from 0.33 mg per millilitre (a sample from the Rio Purús region) to 7.28 mg per millilitre (samples from Pucallpa, Peru), a difference of more than twenty times. The ratio between DMT and the harmala alkaloids varies as well. Two cups from different pots, or from the same pot on different days, are not comparable.
DMT and ayahuasca are different experiences
DMT is also used on its own, usually smoked or vaporised. The differences come from the route of intake and from the MAO inhibition:
- Onset. Smoked DMT acts within a minute or so. Ayahuasca takes roughly 30 to 60 minutes, because it has to pass through the stomach.
- Duration. Smoked DMT is over in well under an hour. In a laboratory study with a single dose of freeze-dried ayahuasca, effects peaked between one and two hours and had resolved by four hours (Riba et al., 2001). Ceremonies last longer, because more than one cup is often served.
- The body. Nausea and vomiting are common with ayahuasca and much less typical of smoked DMT.
- Interactions. The MAO inhibition, and with it the risk of dangerous interactions, belongs to the brew.
Where the practice comes from
Ayahuasca use is documented among many Indigenous peoples of the western Amazon, in what are now Peru, Colombia, Ecuador, Brazil and Bolivia. Practices differ widely: who drinks, who leads, which songs are sung, which plants are added. Among the Shipibo-Konibo of the Ucayali river in Peru, for example, the geometric line patterns known as kené, painted and embroidered on textiles and ceramics, are linked to the songs sung in ceremonies. Peru declared kené part of its cultural heritage in April 2008 (overview).
In 2008 Peru's National Institute of Culture declared the knowledge and traditional uses of ayahuasca by native Amazonian communities part of the country's cultural heritage (Andina, 2008). The declaration protects a traditional practice. It is not an endorsement of retreats for visitors.
In the twentieth century, Brazilian religious movements took up the brew as a sacrament. The best known are Santo Daime, founded in Acre in the 1930s, and the União do Vegetal, founded in 1961. These churches later spread to Europe and North America, and most of the court cases about ayahuasca outside South America involve them. The legal chapter covers those cases.
What this site does not cover
We do not explain how to prepare ayahuasca, how to extract alkaloids or how much of anything to take. A home-made brew combines an MAO inhibitor of unknown strength with a controlled substance of unknown strength, and in most of Europe it is illegal to possess.
Continue with what a ceremony is like, or go straight to safety.