Resources

Quick links

Guidance for completing the application form and updating the record

What are clinical trials?

Guidelines for study registration and reporting

Other public registries and portals

Legislation around clinical trials

Guidance for writing plain English summaries

 

ISRCTN works with a number of stakeholders to improve the information publicly available about clinical trials.

ISRCTN supports open access to clinical trial data information in line with:

  • World Health Organization guidelines - registration of all interventional trials is considered to be a scientific, ethical and moral responsibility.
  • ICMJE statements - for a manuscript to be considered, trial details should be deposited before recruitment starts.
  • Industry recommendations - trial information should be deposited within 21 days of recruitment starting and results be made available within one year of market authorisation.

ISRCTN helps ensure that a number of organisations meet their trial registration objectives:

ISRCTN works to streamline trial registration processes with the following organisations:

  • The National Institute for Health Research through the NIHR Central Portfolio Management System (CPMS) - adoption by the Portfolio ensures that trials can benefit from NHS support and the Portfolio sends trial data batches on behalf of researchers who have opted for ISRCTN registration.
  • The Health Research Authority and its partners through the Integrated Research Application System - IRAS is a centralised system that helps researchers apply for permissions and approvals for health and social care research in the UK. Please see the section below for more information.

ISRCTN engages with the following organisations to make sure that current and future participants are better informed about relevant trials:

  • INVOLVE - advised on how to increase participants' involvement in research.
  • Association of Medical Research Charities - has reported on challenges to communicating the existence and results of research in plain English.
  • NIHR Be Part of Research volunteer registry - available to NIHR-funded or -supported studies. More than 250,000 research-ready participants are signed up to take part in health and social care research. This free service can identify volunteers for your study through the wide range of data it collects including age, ethnic group, sex, location and condition.

ISRCTN maximises the visibility of its clinical trial data by feeding it to other web platforms:

  • WHO clinical trial search portal - ISRCTN data uploaded weekly.
  • Be Part of Research - ISRCTN data uploaded weekly. Be Part of Research aims to list trials that have recruited and are recruiting in the UK and help the UK Government meet its commitment in the NHS Constitution that patients should be made aware of research relevant to them.

ISRCTN follows the development of all publicly available trial registries through its participation in the WHO registry network, in particular:

 

HRA-ISRCTN Registry partnership

From 1 January 2022 the HRA will automatically register clinical trials with the ISRCTN registry as one of the steps to ensure research transparency. This will start with clinical trials of investigational medicinal products (CTIMPs) that are submitted through combined review in the new part of IRAS.

 

Deferred publication of full details in registration of applicable UK clinical trials

The amended UK Clinical Trial Regulations, which came into force on 28 April 2026, introduced new legal requirements for transparency in UK clinical trials of investigational medicinal products (CTIMPs). Sponsors are required to register a clinical trial in a public registry before recruitment of the first participant or within 90 days of approval of the trial, whichever is sooner. The regulations also require the publication of a summary of trial results within 12 months of the end of the trial, unless a deferral has been granted.

The HRA, MHRA and ISRCTN have worked to develop a process that meets UK transparency requirements while temporarily protecting commercially sensitive information. Under this process, trials that are granted a deferral may be registered on ISRCTN with the initial disclosure of only a minimal dataset. The publication of full trial details and a summary of the results may be deferred in accordance with the approved deferral period.

Phase I CTIMPs involving healthy volunteers are automatically eligible for a deferral because of the commercial sensitivity of this stage of medicine development. CTIMPs at other phases may also be granted a deferral of the requirement to either publish full trial details upfront or a summary of results one year after study completion, but are mandated to request their deferral from the HRA ahead of the trial’s commencement.

The new UK transparency requirements apply to CTIMPs conducted in the UK that fall within the scope of the amended Clinical Trials Regulations. Note: Sponsors must comply with all registration and results-reporting requirements unless a deferral or waiver is in place.

Detailed guidance for applicants on uploading minimum fields for deferred trials can be found in the detailed guidance PDF

 

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