ClinicalTrials.gov website screenshot

ClinicalTrials.gov

ClinicalTrials.gov is the U.S. National Institutes of Health (NIH) registry and results database of publicly and privately supported clinical studies of human participants conducted around the world. Operated by the National Library of Medicine (NLM), it provides a modern REST API (data-api v2) that returns study records, study metadata, search areas, and field definitions in JSON. The predecessor classic API remains available for legacy consumers but is being phased out in favor of the v2 API. Data is in the public domain and freely accessible without authentication.

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Clinical TrialsGovernmentHealthNIHOpen DataPublic HealthResearch

APIs

ClinicalTrials.gov Data API v2

The ClinicalTrials.gov Data API v2 is the modern public REST interface to the NIH clinical-studies registry. It exposes study records, study metadata, search areas, study fields...

ClinicalTrials.gov Classic API

The Classic API is the legacy ClinicalTrials.gov interface that preceded the Data API v2 and exposes full-study, brief-study, and field-values endpoints with XML, JSON, and CSV ...

ClinicalTrials.gov Bulk Downloads

ClinicalTrials.gov provides bulk CSV and JSON downloads of the full study registry through the data-api download endpoints. These artifacts support large-scale analytics, archiv...

AACT Database

AACT (Aggregate Analysis of ClinicalTrials.gov) is a publicly available relational database of all ClinicalTrials.gov study content maintained by the Clinical Trials Transformat...

Collections

ClinicalTrials.gov Data API v2

OPEN

Semantic Vocabularies

Clinical Trials Gov Context

0 classes · 7 properties

JSON-LD

API Governance Rules

ClinicalTrials.gov API Rules

9 rules · 3 errors 5 warnings 1 info

SPECTRAL

Resources

🔗
Website
Website
🔗
About
About
🔗
Documentation
Documentation
🌐
Portal
Portal
🔗
Glossary
Glossary
📰
News
News
🔗
Help
Help
📜
PrivacyPolicy
PrivacyPolicy
📜
TermsOfService
TermsOfService
👥
GitHub
GitHub
🔗
JSONLD
JSONLD
🔗
Spectral
Spectral
🔗
LlmsText
LlmsText

Sources

Raw ↑ 
opencollection: 1.0.0
info:
  name: ClinicalTrials.gov Data API v2
  version: 2.0.0
items:
- info:
    name: Search studies
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/studies
    params:
    - name: format
      value: ''
      type: query
      description: Response format
    - name: query.term
      value: ''
      type: query
      description: Free-text search term
    - name: query.cond
      value: ''
      type: query
    - name: query.locn
      value: ''
      type: query
    - name: query.titles
      value: ''
      type: query
    - name: query.intr
      value: ''
      type: query
    - name: filter.overallStatus
      value: ''
      type: query
    - name: filter.geo
      value: ''
      type: query
    - name: fields
      value: ''
      type: query
      description: Comma-separated list of study fields to return
    - name: pageSize
      value: ''
      type: query
    - name: pageToken
      value: ''
      type: query
    - name: countTotal
      value: ''
      type: query
  docs: 'Retrieve a paginated list of clinical study records. Supports

    free-text search, filtering, field selection, and pagination via

    nextPageToken.

    '
- info:
    name: Get a study by NCT ID
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/studies/:nctId
    params:
    - name: nctId
      value: ''
      type: path
    - name: format
      value: ''
      type: query
      description: Response format
    - name: fields
      value: ''
      type: query
      description: Comma-separated list of study fields to return
  docs: Get a study by NCT ID
- info:
    name: Get study field metadata
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/studies/metadata
    params:
    - name: includeIndexedOnly
      value: ''
      type: query
    - name: includeHistoricOnly
      value: ''
      type: query
  docs: Get study field metadata
- info:
    name: Get search areas
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/studies/search-areas
  docs: Get search areas
- info:
    name: Get controlled-vocabulary enumerations
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/studies/enums
  docs: Get controlled-vocabulary enumerations
- info:
    name: Study record sizes
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/stats/size
  docs: Study record sizes
- info:
    name: Field value distribution
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/stats/field/values
    params:
    - name: types
      value: ''
      type: query
    - name: fields
      value: ''
      type: query
  docs: Field value distribution
- info:
    name: Field size statistics
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/stats/field/sizes
    params:
    - name: fields
      value: ''
      type: query
  docs: Field size statistics
- info:
    name: API and data version
    type: http
  http:
    method: GET
    url: https://clinicaltrials.gov/api/v2/version
  docs: API and data version
bundled: true