Clinical trials are observations or experiments done in clinical research. It includes biomedical or behavioral research studies on human participants to answer specific questions about treatments such as novel vaccines, drugs, dietary choices, dietary supplements, and medical devices. It generates data on efficacy and safety. Clinical trials are conducted only after they receive approval from the ethics committee in the country. These authorities are responsible for benefit or risk ratio of trial and the approval does not mean the therapy is safe; it is that only the trial may be conducted. The cost of a trial is dependent on a number of factors. The sponsor for clinical trials may be a pharmaceutical company or government organization or medical device company. There are certain functions which are necessary to the trial include lab work and monitoring, managed by central laboratory or contract research organization.