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Question: What is a clinical trial?


  • A clinical trial (or clinical research study) is a scientific study of how a new medicine or treatment works in people.

  • A clinical trial may also be a comparison between the benefits and risks of two or more treatments.

  • The treatment received by participants in a clinical trial is assigned by chance because, if participants and doctors could choose the treatment, the study could be biased or unfair.

  • Clinical trials help to find new and better ways to prevent, detect, diagnose, control, and treat diseases and medical conditions.

  • If you take part in a clinical trial, you may benefit from a new drug or medical procedure.

  •, developed by a collaboration of all NIH institutes (including the National Library of Medicine), provides patients, family members, health care professionals, and members of the public easy access to information on clinical trials for a wide range of diseases and conditions.

  • See the topic page on Clinical Trials for further information.

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