Psychotria viridis is one of the species that produces N,N-dimethyltryptamine. Its decoction together with other species, such as Banisteriopsis caapi, produces ayahuasca, a beverage used for ritualistic and medicinal purposes. The goal of this study was to understand how environmental factors and cultivation methods influenced the content of N,N-dimethyltryptamine in P. viridis. Over all four seasons, leaf samples were collected from 25 different locations in 14 Brazilian states, and Federal District. Environmental parameters, micro and macronutrients, plant characteristics, information on farming methods were correlated with N,N-dimethyltryptamine content, determined by gas chromatography coupled to mass spectrometry (GC-MS). Greatest effects on the N,N-dimethyltryptamine amount were associated with seasonality, altitude, latitude and biome type. A positive correlation between N and Mg content and N,N-dimethyltryptamine levels was statistically established. By regression analysis, the adequate foliar nutrient levels that would result in the concentration of N,N-dimethyltryptamine in cultivated plants similar to that of Amazonian P. viridis were equated. Keywords: chacrona, ayahuasca, secondary metabolite, DMT IntroductionAyahuasca is a beverage currently used by over 70 different indigenous groups, distributed in Brazil, Bolivia, Colombia, Ecuador, Peru, and Venezuela. 1 The origin of its use has been lost in time, but dates back thousands of years. The oldest evidence dating back to 1500-2000 before Christ is represented by ceramic vessels supposedly used to ingest the beverage.2 Ayahuasca, known in Brazil as "daime", "hoasca", or "vegetal", is a beverage that has been incorporated in religious rituals by several syncretic religious groups in Brazil, such as "União do Vegetal" (UDV), "Santo Daime", and "Barquinha".2 At the beginning of this study, the UDV had approximately 160 sites with extensive cultivation of P. viridis spread throughout Brazil. The UDV cultivates the plants on land that the church owns and maintains exclusively for religious purposes to prepare the ayahuasca beverage. The use of ayahuasca was approved by the Brazilian Government through Resolution No. 1 of January 25, 2010 of the Conselho Nacional de Políticas sobre Drogas (CONAD). Influence of Environmental Factors and Cultural Methods J. Braz. Chem. Soc. 1246 In general, ayahuasca is prepared by a decoction of two plants, a liana classified as Banisteriopsis caapi (Malpighiaceae), which is popularly known in Brazil as "mariri" or "jagube", along with a shrub Psychotria viridis (Rubiaceae), commonly known as "chacrona". The principal psychoactive constituents of B. caapi are harmine, harmaline, and tetrahydroharmine, and of P. viridis is N,N-dimethyltryptamine (DMT). DMT is a psychoactive 5-HT 2A agonist that causes an intense effect characterized by symptoms similar to those produced by lysergic acid diethylamide (LSD). 4 However, at doses used in religious rituals, the psychological effects induced by the DMT content in the beverag...