An adverse event is any change in health that occurs in a person after he or she enrolls in a clinical trial. Not every adverse event is related to the treatment or test being studied, but researchers must report all adverse events to the Food and Drug Administration (FDA). Jump to: navigation, search In medicine, a clinical trial (synonyms: clinical studies, research protocols, medical research) is a research study. ... Jump to: navigation, search The United States Food and Drug Administration (FDA) is the government agency responsible for regulating food (human and animal), dietary supplements, drugs (human and animal), cosmetics, medical devices (human and animal), biologics and blood products in the United States. ...