This is the process of research carried out with new drugs or procedures, which aim to prove they really work, the doses that are effective, are safe and their effects in the body. The entire development process can take several years if the process is successful; the drug is approved and goes on sale.
Any treatment can be tested in a clinical trial. Most clinical studies are designed for a specific disease; however, many of them test new medical procedures or preventive measures.
Before a study medication is proved in humans, it is first widely tested in the laboratory and in animals.