What is a Clinical Trial

A clinical trial refers to studies in which people participate as patients or volunteers.

Different terms are used to describe clinical trials, including:

  • clinical studies
  • clinical research
  • studies
  • research
  • trials
  • protocols

The idea for a clinical trial study—also known as a clinical research study—often originates in the laboratory. After researchers test new therapies or procedures in the laboratory and in animal studies, the most promising experimental treatments are moved into clinical trials, which are conducted in phases. During a trial, more information is gained about an experimental treatment, its risks, and its effectiveness.

Strict rules for clinical studies have been put in place by National Institutes of Health and the FDA. Some studies involve promising new treatments that may directly benefit participants. Others do not directly benefit participants, but may help scientists learn better ways to help people.

Some people participate in clinical trials because none of the standard (approved) treatment options have worked, or they are unable to tolerate certain side effects. Clinical trials provide another option when standard therapy has failed. Others participate in trials because they want to contribute to the advancement of medical knowledge.

Phases of clinical research:

  • Phase 1: Screening for safety
  • Phase 2: Establishing the test protocol
  • Phase 3: Final testing
  • Phase 4: Postapproval studies

For more information about understanding Clinical Trials, please refer to Clinical Trials: What Parents Need to Know (FDA).

The Clinical Trial Volunteer’s Bill of Rights

Any volunteer who gives his or her consent to participare in a clinical trial or who is asked to give his or her consent on behald of another has the following rights:

  • To be told the pupose of the clinical trial
  • To be told about all of the risks, side effects or discomforts that might be resonably expected
  • To be told of any benefits that can be resonably expected
  • To be told what will happen in the study and whether any procedures, drugs, or devices are different than those that are used as standard medical treatment
  • To be told about options available and how they may be better or worse than being in a clinical trial
  • To be allowed to ask any questions about the trial before giving consent and at any time during the course of the study
  • To be allowed ample time, without pressure, to decide whether to consent or not consent to participate
  • To refuse to participate, for any reason, before and after the trial has started
  • To receive a signed and dated copy of the informed consent form
  • To be told of any medical treatments available if complications occur during the trial


FDA: Clinical Research Versus Medical Treatment
Informed Consent: A Guide to the Risks and Benefits of Volunteering for Clinical Trials

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