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Does Your Human Subjects Research Study Meet the NIH Definition of a Clinical Trial?

A research study in which one or more human subjects are prospectively assigned to one or more interventions (which may include placebo or other control) to evaluate the effects of those interventions on health-related biomedical or behavioral outcomes. Learn more

Answer the following four questions to determine if your study is a clinical trial:

  1. Does the study involve human participants?
  2. Are the participants prospectively assigned to an intervention?
  3. Is the study designed to evaluate the effect of the intervention on the participants?
  4. Is the effect being evaluated a health-related biomedical or behavioral outcome?

Your study is considered to meet the NIH definition of a clinical trial even if:
  • Your study uses healthy participants, or does not include a comparison group (e.g., placebo or control)
  • Your study is only designed to assess the pharmacokinetics, safety, and/or maximum tolerated dose of an investigational drug
  • Your study utilizes a behavioral intervention
  • Your study uses an intervention for the purposes of understanding fundamental aspects of a phenomenon (See more information about Basic Experimental Studies with Humans).
Your study is NOT considered to meet the NIH definition of a clinical trial if:
  • Your study is intended solely to refine measures.
  • Your study involves secondary research with biological specimens or health information.


Decision Tool: Does Your Human Subjects Research Study Meet the NIH Definition of a Clinical Trial?

Note for ancillary studies: When answering the following questions, take into account only the work being proposed in the ancillary study, not the work being done in the parent project.