EU CTIS (the Clinical Trials Information System) is where clinical trials in the European Union are registered and published under the Clinical Trials Regulation; the older EudraCT-based EU Clinical Trials Register still holds trials run under the previous Directive. Here is which system holds what, how to search both, and how ClinicaLister cross-references CTIS trials with ClinicalTrials.gov.
CTIS is the single EU system for submitting, authorising and supervising clinical trials under the Clinical Trials Regulation (EU) No 536/2014. It went live on 31 January 2022 with a searchable public website, euclinicaltrials.eu, where anyone can view trial information — subject to exemptions such as personal data and commercially confidential information. Revised transparency rules for what is published apply from 18 June 2024.
Before CTIS, EU trials were registered in EudraCT and published in the EU Clinical Trials Register (clinicaltrialsregister.eu). Trials started under the old Clinical Trials Directive before 31 January 2023 are found there. The three-year transition ended on 31 January 2025: trials still running had to move to CTIS, and the EU Clinical Trials Register continues to display EudraCT trials and their results.
Each CTIS trial has an EU CT number (for example 2025-522058-38-00). A trial that also ran under the Directive keeps its EudraCT number, and many trials are registered on ClinicalTrials.gov as well — with an NCT number.
Search CTIS for current EU trials and the EU Clinical Trials Register for older ones. Both are free.
Open euclinicaltrials.eu/search-for-clinical-trials. Search by EU CT number, or use the advanced search (added in September 2024 with the new public portal) to combine criteria such as condition, product and country, and download the results.
A CTIS record shows the sponsor, the conditions and products, endpoints, member states and their decision dates, and the documents published under the transparency rules.
For trials started under the old Directive before 31 January 2023, search clinicaltrialsregister.eu, for example by EudraCT number. Results for those trials are still posted there.
Look for an NCT number in the CTIS record or search ClinicalTrials.gov for the sponsor's protocol code. Not every EU trial is registered in both places.
Status and per-country decisions change as Member States authorise the trial; revisit the record to see updates.
Where a CTIS trial carries an NCT number, ClinicaLister cross-references it with the ClinicalTrials.gov record, so you can follow one study across both registries.
CTIS trials are linked to drugs in the ClinicaLister graph, each link with a confidence score, so an EU-only trial still shows up on the molecule it tests.
Changes to CTIS trials linked to what you follow appear in the Monitoring view with other regulatory changes.
Through the ClinicaLister MCP server, Claude and other assistants can search EU trials and their drug links in plain language, next to U.S. trials.
11,700+
EU CTIS trials
90%+
of the CTIS public search total
Daily
sync from the CTIS public website
29%
of held CTIS trials carry an NCT number
ClinicaLister holds CTIS records only. It does not import the EudraCT-based EU Clinical Trials Register; EudraCT numbers appear where a CTIS record carries one. Counts as of September 2026; the CTIS public search listed 12,594 trials on October 11, 2026.
The Clinical Trials Information System: the EU's single system for submitting, authorising and publishing clinical trials under the Clinical Trials Regulation. Its public website is euclinicaltrials.eu.
EudraCT was the database for trials under the old Clinical Trials Directive, published in the EU Clinical Trials Register. CTIS replaced it under the Clinical Trials Regulation: it went live on 31 January 2022, and ongoing Directive trials had to transition to CTIS by 31 January 2025.
Yes. clinicaltrialsregister.eu continues to display EudraCT trials, including newly submitted results. Current EU/EEA trials are shown through CTIS.
Many are, but not all. Of the CTIS trials ClinicaLister holds, about 29% carry an NCT number; those are cross-referenced with their ClinicalTrials.gov record.
It is the year followed by three groups of digits, for example 2025-522058-38-00.
Follow EU and U.S. trials of the same drug in one place
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