This article is a contribution to the reflection on the unfolding of the relationships between traditional knowledge, plants, substances, science and the market. The motivation is to think about the changes in relation to ayahuasca since the 1980s. Thus, it questions aspects and implications of the expansion of the use of ayahuasca, especially focusing on the field of what has been called ayahuasca religions. It analyzes the relationship between the expansion of the use of ayahuasca and its contemporary implications, particularly in relation to allopathic medicine and the conversion of participants in these religions from collectors to farmers. This question implies thinking about a selection of plants, homogenizing the biopharmacological properties of the substance, a reification that unfolds into a controversial aspect from an ethnopharmacological point of view. Also in the unfolding of the use of agriculture in a selection of the effects and thus of the experiences with the substance. Keywords: Ayahuasca; Ayahuasca religions; Transformations; Plants; Substances.