ClinicalTrials.gov API

Search ClinicalTrials.gov and pull full study records and posted results as clean JSON.

The API.SH ClinicalTrials.gov API searches registered studies by condition, intervention, title, outcome, sponsor, location or any text, with filters for status, phase, study type, sex, age group, funder type, posted results, healthy volunteers, date ranges and distance from a point. One study by NCT id returns design, arms and interventions, outcomes, eligibility, officials, every location with coordinates, MeSH terms and, on request, the posted results.

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2 endpoints
from $1 / 1,000 calls
1,000 free credits / month
failed calls free

Clinical trial search

GET https://api.api.sh/clinicaltrials/v1/search

{ "success": true }

1 credit · $1 per 1,000 calls

What you can build with the ClinicalTrials.gov API

Pharma pipeline tracking

Search by sponsor, intervention and phase to follow a competitor's trials and their status changes.

/search

Patient recruitment and site finding

Find recruiting studies for a condition within a radius of a location, then read eligibility criteria and site locations.

/search /study

Evidence and results review

Pull posted results with participant flow, baseline, outcome measures and adverse events for completed trials.

/study

Research dashboards

Export trials by phase, status and date range to CSV for Excel, Power BI or Google Sheets.

/search

Medical AI agents

Give an agent trial search and NCT record lookups so it can answer questions about studies with real ids.

/search /study

ClinicalTrials.gov data you get

Field names from real responses. Numbers come parsed, URLs absolute, dates in ISO 8601.

ClinicalTrials.gov API endpoints and prices

Every ClinicalTrials.gov endpoint costs 1 credit per call: credits are $1 per 1,000 on a monthly plan, $2 pay-as-you-go. Pricing

Search and discovery1

Clinical trial search

/clinicaltrials/v1/search

$1 · $2 PAYG

1 credit

More data1

Clinical trial record

/clinicaltrials/v1/study

$1 · $2 PAYG

1 credit

Call the ClinicalTrials.gov API

Clinical trial search: GET https://api.api.sh/clinicaltrials/v1/search

curl "https://api.api.sh/clinicaltrials/v1/search?condition=lung+cancer" \
  -H "x-api-key: $APISH_KEY"

import os, requests

res = requests.get(
    "https://api.api.sh/clinicaltrials/v1/search",
    params={"condition": "lung cancer"},
    headers={"x-api-key": os.environ["APISH_KEY"]},
    timeout=120,
)
res.raise_for_status()
data = res.json()

const url = new URL("https://api.api.sh/clinicaltrials/v1/search");
url.searchParams.set("condition", "lung cancer");

const res = await fetch(url, { headers: { "x-api-key": process.env.APISH_KEY } });
if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);
const data = await res.json();

# Google Sheets (API.SH add-on)
=APISH("/clinicaltrials/v1/search", "condition", "lung cancer")

# Zapier, Make, n8n (verified node): pick the API.SH app,
# choose "ClinicalTrials.gov" and "Clinical trial search".

# AI agents (Claude, ChatGPT, Cursor): add the
# API.SH MCP server https://api.sh/mcp

Create a free accountConfirm your email and get 1,000 free credits every month. No card needed.
Create an API keyOne key works for all 483 platforms.
Send the requestJSON back in one call. Add output=csv or output=ndjson for files.

Why API.SH for ClinicalTrials.gov data

Public data only: no ClinicalTrials.gov login, cookies or account needed
One key and one response shape for ClinicalTrials.gov and 482 other platforms
Built and maintained by API.SH, not third-party publishers
Pay per call; errors on our side cost nothing
Live status for every endpoint

API.SH vs the official ClinicalTrials.gov API

Yes. ClinicalTrials.gov API v2 is a free official REST API from the National Library of Medicine with no key required. API.SH is a convenience layer: named filters instead of query expressions, flattened study fields, and the same key and JSON format you use for PubMed and other sources.

Compared with writing your own v2 client or running an Apify ClinicalTrials.gov scraper, API.SH gives you one key, one JSON shape across research sources and a fixed price per call.

ClinicalTrials.gov API questions

What ClinicalTrials.gov data can I get?+

Study search with condition, intervention, sponsor, location, status, phase and date filters (/clinicaltrials/v1/search) and one full study record by NCT id, optionally with posted results (/clinicaltrials/v1/study).

How much does the ClinicalTrials.gov API cost?+

Every ClinicalTrials.gov endpoint costs 1 credit per call. On a monthly plan 1,000 credits cost $1 (Starter is $50/month for 50,000 credits). Pay-as-you-go is $2 per 1,000 credits, with top-ups from $15 that never expire.

Is there a free trial?+

Yes. Every account gets 1,000 free credits every month. That is 1,000 calls to /clinicaltrials/v1/search at 1 credit each.

Is there an official ClinicalTrials.gov API?+

Yes. The NLM's ClinicalTrials.gov API v2 is free and needs no key. Use it directly if you are happy with its query syntax and nested study format; API.SH is for teams who want simpler filters and one key and format across many data sources.

Do I need an account or API key from ClinicalTrials.gov?+

No. API.SH reads public ClinicalTrials.gov records only. You only need your API.SH key.

Can I search by NCT number?+

Yes. Call /clinicaltrials/v1/study with nct_id for one record, or pass several ids as nct_ids to /clinicaltrials/v1/search.

Can I use it in Excel or Power BI?+

Yes. Responses come as JSON, CSV or NDJSON, so Power BI and Excel can load a search URL directly, and the Google Sheets add-on pulls results into a sheet.

How do I get started?+

1. Sign up at api.sh. 2. Copy your API key from the dashboard. 3. Call /clinicaltrials/v1/search with a condition and status=recruiting, then /clinicaltrials/v1/study with an NCT id. Request examples and every parameter are in the docs at https://api.sh/docs. You can also use the JS or Python SDK, Google Sheets, Zapier, Make, n8n or the MCP server at https://api.sh/mcp.