Hallucinogens are a diverse group of drugs that alter perception (awareness of surrounding objects and conditions), thoughts, and feelings. They cause hallucinations, or sensations and images that seem real though they are not. Hallucinogens can be found in some plants and mushrooms (or their extracts) or can be made by humans. People have used hallucinogens for centuries, mostly for religious rituals. Learn about the health effects of hallucinogens and read the DrugFacts.
- MEDLINEplus Health Information on Substance Use Disorders (National Library of Medicine, NIH)
- Healthfinder.gov (U.S. Department of Health and Human Services)
Clinical trials are research studies in human volunteers conducted to answer specific health questions. Learn about the NIH-sponsored clinical trials available to you.