Ayahuasca is the Quechua word for a liquid produced by slow-cooking or blending the Amazonian Banisteriopsis caapi, as well as the vine itself, which contains harmine, harmaline, and tetrahydroharmine. It is traditionally used throughout the northwestern Amazon, originating from indigenous cultures that have used it for hundreds of years for medicinal and ritual purposes. At the beginning of the last century, syncretic religions that incorporated shamanic worldviews into Christian rituals began to use ayahuasca. At the beginning of the 20th century, these churches expanded into Amazonian urban centers (Labate, 2004) and, in the last thirty years, globally (Labate & Jungaberle, 2011).

Based on the intended use of the decoction or mixture of the vine called ayahuasca, each Amazonian culture, shaman, healer, man or woman with experience in the use of ayahuasca, adds different plants to the infusion with the aim of seeking a specific effect. depending on the disease to cure or ritual to perform. Ethnographic studies suggest that there are more than 5,000 different ways of preparing ayahuasca, all of them using B. caapi as a base (Fericgla, 1997).

Some of these traditional recipes, considering both indigenous cultures and religions that use ayahuasca as their sacrament (or "ayahuasca religions"), include adding leaves from the Psychotria viridis Shrub, which contains DMT (N,N-dimethyltryptamine), along with the vine of B. caapi(Schultes & Hofmann, 1992). Ayahuasca is currently becoming popular as the combination of B. caapi and P. viridis, probably because the international expansion of ayahuasca practices was initiated by these churches (Sánchez & Bouso, 2015).

The precise historical beginning of the use of ayahuasca is unknown. Archaeological evidence has dated the use of ayahuasca to more than 1,000 years (Miller et al., 2019). Among Amazonian ethnic groups, the use of ayahuasca decoctions/mixtures that also contain DMT-laced plants appears to be a more recent phenomenon (Brabec de Mori, 2011).

Ayahuasca is considered a sacred drink by countless Amazonian indigenous groups and a medicine by mestizo healers throughout much of South America. The traditional and modern use of ayahuasca extends from Panama to Bolivia, including Peru, Ecuador, Colombia and Brazil. Countries in which its medicinal use is deeply present in urban centers (Luna, 1986, 2011). A pioneering work from 1986 that brought together all the scientific information on ayahuasca available at that time found more than 400 bibliographic references on the ethnography of ayahuasca (Luna, 1986b), references to more than 70 different Amazonian ethnic groups where it was traditionally used, and more than 40 vernacular names given to the decoction (Luna, 1986c). Ayahuasca is currently used as medicine in ceremonies officiated by indigenous peoples, mestizos, and various professionals who have learned to use it in their traditional places of origin (Labate & Bouso, 2013; Labate & Cavnar, 2014a; Labate, Cavnar & Gearin, 2017; Labate et al., 2009; Luna, 2011).

Source: ICEERs Ayahuasca technical report 2021