Crawling This Site

Note: This page is primarily intended for computer programs designed to visit every study available in ClinicalTrials.gov (i.e., web crawlers.) Human users should see the Find Studies section for help with basic and advanced searches for clinical studies.

ClinicalTrials.gov makes it easy for Web crawlers to find all the studies included on the site. Each time a study collection is updated, pages of links to all studies are generated. In addition, ClinicalTrials.gov assigns to each study a unique number, called the ClinicalTrials.gov Identifier (NCT Number), in the format NCTxxxxxxxx, where each "x" is a number.

Use of ClinicalTrials.gov data is subject to these Terms and Conditions. If you Linking to This Site please provide proper attribution to the National Library of Medicine and ClinicalTrials.gov.