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For Participants

Clinical trials evolve from research that begins in a lab. They provide a path for innovation and discovery to reach people all over the world. 

Through clinical trials, researchers seek to find safe and effective ways to prevent, detect or treat disease. They do this through recruiting participants, like you, to take an active role in your healthcare and, at the same time, add to our knowledge about the treatments for disease.

Clinical trials are conducted in a series of phases that are designed to investigate how treatment or therapy affects patients:

  • Phase 0/Early Phase 1 trial: A phase of research used to describe exploratory trials conducted before traditional phase 1 trials to investigate how or whether a drug affects the body. They involve very limited human exposure to the drug and have no therapeutic or diagnostic goals (for example, screening studies, microdose studies).
  • Phase 1 trial: A phase of research to describe clinical trials that focus on the safety of a drug. They are usually conducted with healthy volunteers, and the goal is to determine the drug's most frequent and serious adverse events and, often, how the drug is broken down and excreted by the body. These trials usually involve a small number of participants.
  • Phase 2 trial: A phase of research to describe clinical trials that gather preliminary data on whether a drug works in people who have a certain condition/disease (that is, the drug's effectiveness). For example, participants receiving the drug may be compared to similar participants receiving a different treatment, usually an inactive substance (called a placebo) or a different drug. Safety continues to be evaluated, and short-term adverse events are studied.
  • Phase 3 trial: A phase of research to describe clinical trials that gather more information about a drug's safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs. These studies typically involve more participants.
  • Phase 4 trial: A phase of research to describe clinical trials occurring after the FDA has approved a drug for marketing. They include postmarket requirements and commitment studies that are required of or agreed to by the study sponsor. These trials gather additional information about a drug's safety, efficacy, or optimal use.

As an academic medical center, UCI Health is uniquely positioned to advance medicine through leading-edge research and clinical trials.