Reviewed: 12 August 2005

TRIAL PHASES:  <Go To Next Section>

There is a series of steps, or "phases", involved in testing a new treatment in humans. As clinical research can involve potential increased or unknown risks for patients, the trials are very carefully designed to try to lower, as much as possible, the chance that participants will be harmed by a new therapy. It is very important for each of the different phases of testing to take place, so that at the end, doctors and patients will be assured that a new treatment is reasonable and effective. For a trial to proceed in humans, it must satisfy several levels of regulations to insure maximum safety, and that the testing is ethical. The remainder of this discussion will largely centre around the testing of new drugs, as these form the basis for the greatest number of clinical trials.