The objective of clinical trials is to find ways to prevent, diagnose, or treat disease more effectively. clinical trials are regulated by specific regulatory authorities. clinical trial is a kind of experimental research and the most vital type of research to prove the cause-and-effect relationship between therapeutic intervention and treatment. the subjects who enter the study are divided into two groups: one group is exposed to therapeutic intervention and the other group as a control group. Finally, the results of the intervention are evaluated by comparing the groups.