Over-the-counter (OTC) medicines are those that can be sold directly to people without a prescription. OTC medicines treat a variety of illnesses and their symptoms, including pain, coughs and colds, diarrhea, constipation, acne, and others. Some OTC medicines have active ingredients with the potential for misuse at higher-than-recommended dosages. Learn about the health effects of OTC medicines Dextromethorphan (DMX) and Loperamide and read the DrugFacts on Over-the-Counter Medicines.
- 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 NIDA-sponsored clinical trials available to you