Clinical trials are research studies that test a medical, surgical, or behavioral intervention in people. Clinical trials are research studies that explore whether a medical strategy, treatment or device is safe and effective for humans.See our clinical trials. Clinical trials are studies to test new drugs, already approved drugs, devices, or other forms of treatments. Resources for patients and the public on how to find clinical trial opportunities and what to expect as a participant. Clinical research is the comprehensive study of the safety and effectiveness of the most promising advances in patient care. Clinical trials happen in several phases during which different questions are asked. Each phase builds on the results of previous phases. Explore what clinical trials are, how they operate, and their crucial role in medical advancements. Learn about the phases and participant roles with Roche.