Clinical trials are prospective biomedical or behavioral research studies
on human participants designed to answer specific questions about biomedical
or behavioral interventions, including new treatments (such as novel vaccines,
drugs, dietary choices, dietary supplements, and medical devices) and known
interventions that warrant further study and comparison. Clinical trials
generate data on dosage, safety and efficacy. They are conducted only after
they have received health authority/ethics committee approval in the country
where approval of the therapy is sought. These authorities are responsible for
vetting the risk/benefit ratio of the trial—their approval does not mean the
therapy is 'safe' or effective, only that the trial may be conducted.