ClinicalTrials.gov
The world's largest public database of clinical studies, maintained by the U.S. National Library of Medicine, where researchers are required to register their trials.
In Detail
ClinicalTrials.gov is a comprehensive, publicly accessible database of clinical studies conducted in the United States and around the world. Maintained by the National Library of Medicine (NLM), part of the National Institutes of Health (NIH), the database was established in 2000 as a result of the FDA Modernization Act of 1997. As of 2026, ClinicalTrials.gov contains records for over 500,000 research studies from more than 220 countries. Federal law (Section 801 of the FDA Amendments Act of 2007) requires the registration of clinical trials involving FDA-regulated drugs, biologics, and devices, including reporting of results within one year of completing the trial. Each study listing includes detailed information about the trial's purpose, eligibility criteria, locations, sponsor, study design, primary and secondary endpoints, enrollment status, and contact information. ClinicalTrials.gov uses a standardized protocol registration format and assigns each study a unique NCT (National Clinical Trial) identifier. The database is searchable by condition, treatment, location, phase, and other criteria. In 2023, ClinicalTrials.gov launched a modernized version (known as "beta" or the v2 API) with improved search functionality and a redesigned user interface. TrialFinderData draws all of its trial data from the ClinicalTrials.gov API v2 and translates the clinical jargon from eligibility criteria into plain English. The database is an invaluable resource for patients, caregivers, and healthcare providers seeking information about available clinical trials, and its open data policy makes it accessible to researchers and public health organizations worldwide.
Frequently Asked Questions
What does "ClinicalTrials.gov" mean in clinical trials?
The world's largest public database of clinical studies, maintained by the U.S. National Library of Medicine, where researchers are required to register their trials.
Why is "clinicaltrials.gov" important for patients?
Understanding clinicaltrials.gov helps patients and caregivers navigate clinical trial participation with confidence. It is part of the broader clinical research process that ensures treatments are safe and effective before reaching patients.
Related Terms
Clinical Trial
A research study that tests a medical treatment, drug, device, or intervention in human volunteers to determine whether it is safe and effective.
Inclusion Criteria
The specific characteristics that a person must have to be eligible for a clinical trial, such as age range, diagnosis, or stage of disease.
Exclusion Criteria
The characteristics that disqualify a person from participating in a clinical trial, such as certain medical conditions, medications, or pregnancy.
FDA Approval Process
The regulatory pathway through which the U.S. Food and Drug Administration evaluates and approves new drugs, biologics, and medical devices for public use.
this entity is one of the U.S. clinical trials and research registries concepts that recurs across this site. The definition above is the technical answer; the paragraphs below add the practical context for how the concept connects to the the NIH ClinicalTrials.gov registry data behind every per-entity page on the site.
In the the NIH ClinicalTrials.gov registry data, this concept shapes one or more of the fields that drive the per-entity grades and rankings on this site. The methodology page describes which fields feed into which output; this glossary entry documents the underlying term.
Source: ClinicalTrials.gov, 2026.