A large global survey of over 10,800 ayahuasca users from more than 50 countries found that acute physical adverse effects, primarily vomiting, occurred in 69.9% of participants, with 2.3% needing medical attention. Adverse mental health effects in the weeks or months after use were reported by 55.9% of the sample, but about 88% of those viewed these effects as part of a positive growth or integration process; around 12% sought professional support. Physical adverse effects were linked to older age at first use, having a physical health condition, higher lifetime and recent use, a prior substance use disorder diagnosis, and using ayahuasca in unsupervised settings.
Indigenous-Amazonian medicine is an intricate medical system built on a sophisticated understanding of health, illness, and treatment. Traditional healers describe multifactorial causes of illness, complex interactions between material and spiritual aspects of body and nature, and treatments that often involve carefully designed applications of 'teacher plants'. Healers view traditional and biomedical systems as complementary, but identify lack of recognition as a primary barrier to collaboration. Preconceptions, stigma, and insufficient research impede countries from meeting Indigenous health needs and perpetuate inequalities. The findings highlight Amazonian healers' unique expertise with psychoactive plants, offering lessons for the revival of psychedelic-assisted therapies.