Every year, we publish a report on the registration status of clinical trials in the UK. This is part of our ongoing commitment to promote research transparency.
Over the past 12 months, we’ve done lots of work on our processes to collect registration information with the goal to support sponsors to be transparent.
This includes actively contacting sponsors one year after receiving their Research Ethics Committee(REC) favourable opinion, to remind them of their responsibilities to register their trial.
We also looked at how to best present information about whether sponsors have met the requirement to register trials, to understand the patterns and changes, as well as the nuances involved in collecting this data.
The report covers data collected on all clinical trials receiving a favourable opinion from a REC in 2023. There are 1314 trials in total.
Here are the headlines from this year's clinical trial registration report:
- 92% of studies are registered or in the process of being registered
- we saw a reduction in the number of trials providing us with no reason for registration (4% compared to 10% last year)
- the two most used registries are ClinicalTrials.gov (72%) and ISRCTN (25%)
- compliance is higher for commercially sponsored clinical trials than non-commercially sponsored trials, and for Clinical Trials of Investigational Medicinal Products (CTIMPs) rather than non-CTIMPs
Clive Collett, Head of Policy and EngagementWe now have a way to track registration data going forward so we can monitor whether our work and initiatives, such as our Make it Public workshop on the barriers to registration of clinical trials, is helping to improve research transparency practices. We believe that publishing this data will encourage higher rates of compliance with transparency requirements
Jane Morrin O'Rourke, Senior Policy ManagerIn this year’s report, for the first time, we looked at the difference between commercial and non-commercial studies, and the difference between CTIMPs and non-CTIMPs.
We wanted to get a better understanding of how different sponsors are doing and where support to comply with the condition to register could be targeted. We also wanted to understand if compliance varied between the type of clinical trial. From April 2026 it will be a legal requirement for CTIMPs to be registered. We will look into the reasons for these differences in registration rates and where we can provide further support to sponsors.
The bigger picture for research transparency
Registration of clinical trials is of course just one element of transparency, and there are other actions equally important in making sure that research information is publicly accessible throughout the study lifecycle.
We expect sponsors to publish results of their studies 12 months after the end of the study. We are continuing our work to better show and encourage compliance in this area. We will be sharing more about this work in the coming year.
We’ll also be looking at another key pillar of research transparency – feeding back to participants- for our next Make it Public campaign. Anecdotally, we know this is an area requiring improvement, and we know that telling people about the findings of research they take part in is an important part of doing research in a people-centred way. Seven in ten of the UK public tell us that knowing that participants will be told about the findings makes them feel more confidence in research findings. More details will be shared on this soon.
We are also preparing for the new Clinical Trials regulations, which will be implemented in spring 2026, and will feature specific requirements for research transparency.
For the first time, it will be a legal requirement to:
- register clinical trials in a public registry
- publish a summary of trial results within 12 months of completion
- share a summary of results with participants in a format they can easily understand
Provisions for deferrals and exemptions in specific circumstances, such as national security, will be available. We are preparing guidance to support researchers in meeting these new requirements.