Skip to content
Assyro AI

Search ClinicalTrials.gov

Search and read ClinicalTrials.gov records through the Assyro API: registered studies, cited by NCT number.

GEThttps://api.assyro.com/v1/sources/clinicaltrials/search

Preview: api.assyro.com is not serving production data yet. This page follows the API's published description and may change before launch.

Search and read ClinicalTrials.gov records from your own code: registered studies, cited by NCT number. Published by U.S. National Library of Medicine (ClinicalTrials.gov) (clinicaltrials.gov); answered from Assyro's copy, refreshed daily 13:40 UTC.

Attribution required: every record carries attribution. Show it wherever you show the data: "Source: ClinicalTrials.gov, a service of the U.S. National Library of Medicine; data as processed by ClinicalTrials.gov on the date in version. Reformatted by Assyro, content not modified." See the terms.

Example: "Which phase 3 trials tested tirzepatide in obesity?"

Search

GET https://api.assyro.com/v1/sources/clinicaltrials/search with any of these query parameters. Repeat a parameter for a list (?phase=PHASE2&phase=PHASE3). An unknown parameter is refused by name.

Search parameters

  • querystring

    Free text searched across the whole record, e.g. "semaglutide cardiovascular outcomes".

  • conditionstring

    Disease or condition, e.g. "obesity", "non-small cell lung cancer".

  • conditionsstring[]

    Several conditions at once, up to 5: one search per condition, run together, with every other filter applied to each (e.g. tirzepatide in ["heart failure", "sleep apnea", "MASH"]). Use it instead of searching one condition per step.

  • interventionstring

    Drug, device, biologic or procedure name, e.g. "tirzepatide".

  • interventionsstring[]

    Several interventions at once, up to 5: one search per intervention, run together, with every other filter applied to each.

  • sponsorstring

    Lead sponsor or collaborator, e.g. "Novo Nordisk".

  • phasestring[]

    Keep studies in any of these phases. NA means phase not applicable (e.g. device or behavioural). One of: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA.

  • statusstring[]

    Keep studies with any of these overall recruitment statuses.

  • studyTypestring

    Keep one study type. One of: INTERVENTIONAL, OBSERVATIONAL, EXPANDED_ACCESS.

  • startDateFromstring

    Earliest study start date, YYYY-MM-DD.

  • startDateTostring

    Latest study start date, YYYY-MM-DD.

  • hasResultsboolean

    true keeps only studies with results posted on ClinicalTrials.gov; false keeps only those without.

  • sortstring

    relevance (default; most recently updated first when no text is given) or newest (most recently updated first, even with text). One of: relevance, newest.

  • limitinteger

    Number of studies to return (default 8).

  • offsetinteger

    Skip this many results (for paging), default 0.

Each result is a record; read one in full with Get a record.

What a record holds

  • id, title, url: the source's identifier, its title and its page at the source, to verify it.
  • authority, publishedDate, version: who published it, when, and the edition read.
  • snippet and fields: the matching text and the source's own fields.
  • asOf: the day Assyro's copy of the source was read.
  • attribution: the attribution the licence requires.