The consumption of ayahuasca, a hallucinogenic beverage used by indigenous communities in the Amazon, is increasing worldwide due to the expansion of syncretic religions founded in the north of Brazil in the first half of the twentieth century, such as Santo Daime and União do Vegetal. Another example is the jurema wine, a drink that originated from indigenous cultures of the northeast of Brazil. It is currently used for several religious practices throughout Brazil involving urban neo-shamanic rituals and syncretic Brazilian religions, such as Catimbó and Umbanda. Both plant products contain N,N-dimethyltryptamine which requires co-administration of naturally occurring monoamine oxidase inhibitors, for example β-carboline derivatives, in order to induce its psychoactive effects in humans. This review explores the cultural use of tryptamines and β-carbolines and focuses on the analytical techniques that have been recently applied to the determination of these compounds in ayahuasca, its analogues, and the plants used during the preparation of these beverages.