In 1999, ClinicalTrials.gov was founded as an Internet-based resource that provide information about clinical research studies to the public, researchers, and health care professionals.

The Web site is maintained by the National Library of Medicine (NLM) at the National Institutes of Health (NIH). Information on ClinicalTrials.gov is provided and updated by the sponsor or principal investigator of the clinical study.

The ClinicalTrials.gov database includes information about clinical research studies that are happening now, will happen soon, or happened in the past. Information about each study is permanently available in the database, even after the study ends.