Ayahuasca, or yagé, is a hallucinogenic drink mainly consumed during shamanic rituals for therapeutic and divinatory purposes. Traditionally, this drink is prepared from Banisteriopsis caapi vines, sources of -carbolines (harmine, harmaline and tetrahydroharmine) mixed with various leaves from plants such as Psychotria viridis that contain N,N-dimethyltryptamine (DMT). Following the investigations of a Parisian historian, three bottles containing ‘‘yagé’’ were found in the home of a French pharmacist who lived at the beginning of the 20th century. The laboratory of toxicology of the Institute of Legal Medicine of Strasbourg was asked to analyse the contents of the bottles in order to determine the presence of ayahuasca alkaloids and, after the dosage, to determine the state of conservation of the beverages. The samples were analysed for ethanol by HS-GC/FID, for solvents by HS-GC/MS and for the main psychoactive substances by LC-HRMS and LC-MS/MS after appropriate dilutions in water. The ethanol test was positive for all solutions with an alcohol content between 67.3◦ and 81.1◦. The alkaloid test revealed the presence of harmine in all three samples with concentrations between 0.13 and 1.5 g/L, harmaline and tetrahydroharmine only in two samples with concentrations between 53 and 80 mg/L for the first compound and between 49 and 142 mg/L for the second. DMT as well as 5-OH-DMT and 5-MeO-DMT were not found in any of the three samples. These analyses suggest a probable total absence of plants containing tryptamines and a complex composition of -carbolines due to degradation and interconversion processes.