Clinical Trials
Medical research studies are categorized in four phases.
On average, it takes 15 years before a drug tested in the laboratory can be tested on humans. Only five in every 5,000 compounds tested in the lab ever make it to human testing. Only one in five of those are approved for sale in the United States.
After initial laboratory and animal studies, medicines that are tested in people must follow rigid guidelines set by the U.S. Food and Drug Administration (FDA).