Clinical trials are done for testing of drugs and medical device and advanced treatment that would be available to human in future. Scientists are constantly working to find new and improved treatment for disease and their research can only be tested through clinical trials. People who participate in clinical trials are receiving new treatment , medical care and advanced therapies before it is available to anyone. In order to assure the safety they also receive medical follow up . Clinical trials plays an important role in evaluating drugs and diagnostic tools to bring discovery into clinical practice and influence health laws and funding for health services . Clinical trials have drawbacks like uncertainty of new drug or treatment which can cause death of volunteers .Patients have to stick to trail schedule and spending money for travelling to clinical trial sites . Many clinical trials are failed either lesser number of patient involved or due to patient’s death or serious factors costs millions of dollars to industry .