On 28 April 2026, the most significant update to UK clinical trials regulations in two decades comes into force.
The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 will establish a new pathway for how trials involving medicinal products are set up and delivered across the UK, with the regulations set to benefit all those involved in trials from patients and health professionals to the researchers and pharmaceutical industry.
An encouraging increase in clinical trial activity was seen in 2025, even before the new regulations take effect, with data from the Medicines and Healthcare products Regulatory Agency (MHRA) showing applications rose particularly in respect of early and innovative research. Companies are also going to regulators earlier for help, with a sharp rise in the number of MHRA scientific advice meetings concerning clinical trials, enabling developers to get the design of their trials right first time and avoid costly delays.
Key changes to the regulations
Under the new rules, key changes coming this year include:
- A fast-track notification route which will allow lower-risk trials to start sooner and this is expected to benefit about 20% of studies
- A 14-day assessment route for phase 1 trials will also be introduced by the MHRA
- There will be better use of early safety data from overseas studies that meet UK standards
- New MHRA capability will be able to assess computer model simulations, such as in-silico trials, to help predict how new medicines may behave before they are tested in patients, reflecting how medicines are developed today
- Experts will have time to focus and advise on complex and early-phase studies
The implementation of the latest international Good Clinical Practice (GCP) guidelines will come into force in the UK, along with the updated regulations. All trials will need to adhere to GCP principles with trials for marketing authorisation needing to comply with the full guidelines. The new regulations will require compliance with the Declaration of Helsinki, the international ethical standards for medical research, unless these contradict the regulations. Greater transparency of clinical trial results will also help boost participation, inclusion and diversity.
The MHRA and Health Research Authority (HRA) have published guidance which sets out the updates to the regulations and provides practical information on how they should be implemented. MHRA guidance focuses on issues relevant to MHRA applications and the reporting of key events such as safety information. HRA guidance covers issues related to the Research Ethics Committee review of applications, as well as the new transparency requirements with both sets of guidance aligned to streamline the process.
Conclusion
The MHRA will be considered to have largely delivered on its commitment to implement 'a flexible and risk-proportionate regulation of clinical trials, which accelerates patient access to potentially life-saving medicines without compromising safety'. The reforms are designed to demonstrate that the UK is a safe, quick and efficient place to conduct clinical trials. The clinical trial community should ensure it uses the guidance to prepare for the changes and update their policies, procedures and systems as required.
