This project examines the transformations in scientific discussions around traditional uses of psychoactive plants in Mexico during the first half of the 20th century. It seeks to identify how the disciplines of medicine, pharmacology and botany have researched peyote and other local psychedelics and then it will turn to anthropological studies. It analyzes both the studies carried out by Mexican scientists, as well as by foreign researchers who visited this country rich in psychoactive natural species, and the links between these doctors, ethnobotanists and anthropologists. It aims to investigate traditional and indigenous uses of natural drugs, how diverse disciplines have seen these plants as objects of study, and how scientific perspectives for approaching these species have transformed over time. This project will contribute to a better understanding of the past and present drug policies and will connect with the current psychedelic renaissance.