Clinical trials follow a plan known as a protocol. The protocol is carefully designed to balance the potential benefits and risks to participants, and answer specific research questions. A protocol describes the following:

  • the goal of the study
  • who is eligible to take part in the trial
  • protections against risks to participants
  • details about tests, procedures, and treatments
  • how long the trial is expected to last
  • what information will be gathered

A clinical trial is led by a principal investigator. Members of the research team regularly monitor the participants’ health to determine the study’s safety and effectiveness.

Reproduced with permission from NIH Clinical Trials and You. NIH does not endorse or recommend any products, services, or information described or offered here by Healthline. Page last reviewed on October 20, 2017.