ISRCTN Registry API

Base URL

https://www.isrctn.com/api/query

Authentication

No API key or account. ISRCTN is a public registry operated by BMC; consult its terms before bulk redistribution of records.

Rate limit

No published limit. Use targeted queries with `limit` rather than harvesting the whole register repeatedly.

Pricing

Free to query, with no registration.

CORS

Enabled — callable directly from browser JavaScript

Official docs

Read the docs

Every request below was executed against the live API on 21 Aug 2026, and the response shown is the real body it returned — not an illustration.

curl 'https://www.isrctn.com/api/query/format/who?q=cancer&limit=1'

const res = await fetch("https://www.isrctn.com/api/query/format/who?q=cancer&limit=1");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);

import requests

res = requests.get("https://www.isrctn.com/api/query/format/who?q=cancer&limit=1", timeout=20)
res.raise_for_status()
print(res.json())

<trials><trial>
  <main>
    <trial_id>ISRCTN99067257</trial_id>
    <utrn/>
    <reg_name>ISRCTN</reg_name>
    <date_registration>20/08/2026</date_registration>
    <primary_sponsor>University of Leeds</primary_sponsor>
    <public_title>REASCENT trial: a proof of principle trial to treat active systemic sclerosis via interferon inhibition</public_title>
    <acronym>REASCENT</acronym>
    <scientific_title>REASCENT trial: a proof of principle trial to treat active systemic sclerosis via interferon inhibition</scientific_title>
    <date_enrolment>27/09/2025</date_enrolment>
    <type_enrolment>Actual</type_enrolment>
    <target_size>35</target_size>
    <recruitment_status>Recruiting</recruitment_status>
    <url>https://www.isrctn.com/ISRCTN99067257</url>
    <study_type>Interventional</study_type>
    <study_design>Interventional randomized controlled trial (Safety)</study_design>
    <phase>Phase II</phase>
    <hc_freetext>Systemic sclerosis</hc_freetext>
    <i_freetext>This is a single-arm, open-label, proof-of-principle trial to evaluate the safety and tolerability of an intravenous (IV) treatment regimen of anifrolumab 300 mg in patients with active systemic sclerosis (SSc) while receiving standard of care (SOC) treatment. Participants enrolled in REASCENT will receive a fixed intravenous dose of anifrolumab 300 mg every 4 weeks (Q4W) for a total of 13 doses (Week 0 to Week 48).</i_freetext>
    <results_actual_enrolment>0</results_actual_enrolment>
    <results_date_completed>31/08/2028</results_date_completed>
    <results_url_link/>
    <results_summary/>

trial_idstring

The ISRCTN identifier, such as `ISRCTN99067257`. The registry's permanent reference.

utrnstring

Universal Trial Number, when the sponsor obtained one. Frequently empty.

date_registrationstring

Registration date in `DD/MM/YYYY` format. Registration after enrolment began is itself informative.

primary_sponsorstring

Organisation responsible for the trial.

public_title / scientific_title / acronymstring

Lay title, full scientific title and short name.

recruitment_statusstring

Such as `Recruiting`, `Not yet recruiting` or `Completed`.

study_type / study_design / phasestring

Design metadata — `Interventional`, `randomized controlled trial (Safety)`, `Phase II` and similar.

target_size / type_enrolmentstring

Planned or actual enrolment, with `type_enrolment` saying which of the two it is.

hc_freetext / i_freetextstring

Health condition studied and a free-text description of the intervention.

results_url_link / results_summarystring

Links to published results. Often empty, including for completed trials.

• Find registered trials for a condition or intervention
• Check whether a trial was prospectively registered before enrolment
• Pool records with other registries using the shared WHO schema
• Monitor recruitment status for trials of interest
• Compare a published paper's outcomes against the registered protocol

If ISRCTN Registry does not fit, these health & medical apis cover similar ground. Every one was called before publishing, and each links to its own reference page with a working curl command and the response it returned.