Are all clinical trials the same?

There are four different types of clinical trials, each one associated with a different phase in the development of a new medicine or treatment:

Phase 1: Determines the safety of the medicine, how it works and how well it is tolerated in small groups of people.

Phase 2: Determines the effectiveness of the medicine and further evaluate the safety in a larger group of people

Phase 3: Determines the effectiveness, monitors side-effects and compares it to commonly used treatments in large groups of people

Phase 4: Post marketing studies reflect additional information including the drugs risks, benefits and optimal use