The terms ‘trial’ and ‘study’ are interchangeable. A clinical study is performed to test the safety and effectiveness of a new experimental drug or combination of drugs or therapy. Ethical studies always have a document called the “study protocol” which describes the characteristics and number of participants being sought for the trial; the expected duration of the trial; the experimental drugs or therapy involved (under trial); the dose levels being studied; and the desired and expected (hypothesised) outcomes and effects of the study. A study protocol also includes a list of events under which the trail will be suspended or stopped. Anyone participating in a study has a right to be advised of the protocol and their rights in participating before entering the trial. Participants of any study can also withdraw at any time, which is one of the rights of participating in a study.