Dimethyltryptamine

Ayahuasca

Indigenous peoples of the Amazon have used dimethyltryptamine for spiritual and medicinal purposes for thousands of years [ ]. South American powdered snuffs are usually prepared from the seeds of Anadenanthera peregrina or the bark of Virola trees. Ayahuasca is the name given by the Quechua to any of various psychoactive infusions or decoctions prepared from plants that are found in the Amazon Rainforest. Ayahuasca prepared from Banisteriopsis caapi vines and Psychotria viridis contains reversible beta-carboline alkaloids (harmine, tetrahydroharmine, and harmaline, from the former), which inhibit monoamine oxidase type A, thus enabling the oral absorption of dimethyltryptamine (from the leaves of the latter) [ ]; this gives hallucinogenic effects for 3–4 hours [ ]. In some parts of South America Diplopterys cabrerana is used instead of Psychotria viridis [ ]. In the USA dimethyltryptamine is found in common plants such as Phalaris arundinacea , Phalaris tuberosa , or Phalaris aquatica (canary grass) [ ].

Animal studies of the median lethal dose of dimethyltryptamine and of several harmala alkaloids suggested that the lethal dose of these substances in humans is probably greater than 20 times the typical ceremonial dose [ ].