ClinicalTrials.gov search with cited AI answers
Search ClinicalTrials.gov records by asking a question. ClinicalEvidence reads the matching records, writes an answer where every sentence links to an NCT number, and lays out every study in a trial table that maps the registry fields you already know.
What makes a manual ClinicalTrials.gov search slow
ClinicalTrials.gov is the largest public trial registry and the first place most professionals look. It is maintained by the US National Library of Medicine at the National Institutes of Health, and each study has an NCT number: the letters NCT followed by eight digits. The registry is excellent at holding records. It does not summarize them for you.
- A condition and intervention search can return hundreds of records to open one by one
- Drug names, codes and class terms need separate searches to catch everything
- Outcomes are posted for some studies and only published in journals for others
- Comparing several studies means copying fields into a spreadsheet
ClinicalEvidence keeps the registry as the source of truth and removes the copying.
What the ClinicalTrials.gov registry fields mean
Knowing the fields helps you read any answer critically. These are the parts of a record that matter most for evidence work.
- Study type: interventional, observational or expanded access
- Phase: early phase 1, phase 1, phase 2, phase 3 or phase 4, or not applicable for many device and behavioural studies
- Overall status: for example not yet recruiting, recruiting, active not recruiting, completed, terminated, suspended or withdrawn
- Conditions and interventions: what is studied and with which drug, device, procedure or behaviour
- Eligibility criteria: who can enrol, with age, sex and inclusion and exclusion rules
- Primary and secondary outcome measures: what the trial measures and over what time frame
- Enrolment: the actual or anticipated number of participants
- Sponsor and collaborators: who runs and funds the study
- Start, primary completion and study completion dates
- Locations: the sites listed for the study
- Results: summary results, when they have been submitted and posted
For applicable clinical trials, US law under FDAAA 801 requires registration and, in most cases, results reporting on ClinicalTrials.gov, which is why the results field is often the first public source of outcomes.
How our trial table maps the registry fields
Every study that supports your answer becomes a row in the clinical trial table. The columns follow the registry, so nothing is renamed beyond recognition.
| Trial table column | ClinicalTrials.gov field |
|---|---|
| Phase | Phase |
| Population | Conditions and eligibility criteria |
| Interventions | Interventions and arm groups |
| Primary endpoints | Primary outcome measures |
| Secondary endpoints | Secondary outcome measures |
| Results posted | Results section present |
| Sponsor | Lead sponsor |
| Status | Overall status |
| Enrolment | Enrolment, actual or anticipated |
| Dates | Start, primary completion and completion dates |
| Locations | Locations |
Sort by any column, filter by condition, intervention, phase, status, study type, date range, sponsor type, country and results available, and open the original record from each row.
How a cited ClinicalTrials.gov answer is built
Our index holds ClinicalTrials.gov records, refreshed every day, alongside PubMed, PubMed Central open access full text, the EU Clinical Trials Register and the WHO ICTRP where licences allow. Semantic and full text search find the relevant records, and the answer is written only from retrieved passages.
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Automatic citation verification checks that each NCT number exists in the index and that the cited passage supports the sentence
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An answer without verified sources is not shown
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When no record answers your question, you are told so plainly, never answered from model memory
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Where a trial has a linked publication, the answer can cite its PMID next to the NCT number
For a step by step guide to the registry itself, read how to search ClinicalTrials.gov.
An independent tool, not the official registry
ClinicalEvidence is not affiliated with, endorsed by or operated by the National Library of Medicine, the National Institutes of Health or ClinicalTrials.gov. We index public registry records and link every claim back to the original record so you can check it at the source.
Who uses ClinicalTrials.gov search with AI
- Clinical development and CRO feasibility teams reviewing competing trials
- Medical affairs teams answering questions with registry evidence
- Physicians, pharmacists and researchers checking what trials exist for a question
- HEOR and regulatory consultants scoping the trial landscape
It is a professional research tool and does not give medical advice.
Plans for ClinicalTrials.gov search
Save 50% with yearly billing.
- Clinician, 49 USD per month or 24 USD per month billed yearly (288 USD)
- Research Team, 199 USD per month or 99 USD per month billed yearly (1 188 USD)
- Organization, 499 USD per month or 249 USD per month billed yearly (2 988 USD)
- Enterprise, 1 490 USD per month or 745 USD per month billed yearly (8 940 USD)
Full limits are on the pricing page.
ClinicalTrials.gov search questions
Is ClinicalEvidence the official ClinicalTrials.gov website?
No. ClinicalEvidence is an independent tool. It is not affiliated with the National Library of Medicine or the NIH, and every answer links to the original record on the registry.
How fresh are the ClinicalTrials.gov records?
The index is refreshed every day, so new registrations, status updates and newly posted results reach your answers within a day.
Can I search by NCT number?
Yes. Ask about a specific NCT number and the answer and trial table start from that record, together with related studies and linked publications.
Does it show trial results?
The trial table shows whether results are posted for each study, and you can filter to studies with results available. Answers cite the registry record and, where one exists, the publication.
Can I export what I find?
Yes. Every plan exports CSV, RIS and BibTeX, and Research Team and higher add XLSX and DOCX with a reference list.
Search ClinicalTrials.gov by asking a question
Run the one-time demo and see an answer with every NCT number linked.