For over a century, the agency has conducted clinical studies that explore the nature of illnesses. There are several types of clinical trials. By far the largest number are those that test new drugs. Prevention studies look at drugs or lifestyle changes that may help prevent disease.
Diagnostic studies look at ways of detecting or finding out more about disease.
Treatment studies may monitor new drugs or evaluate new combinations of established treatments. FDA, which some have called the world's largest consumer protection agency, works to protect the public by ensuring that products are safe, effective, and labeled for their intended use. From Animals to Humans Every year, hundreds of clinical trials are conducted at medical centers across the country. Drugs must be studied in properly controlled trials in order to determine if they work for a specific purpose. NIH or the company developing the drug must conduct studies to show any interaction between the body and the drug.