Transforming the UK's clinical trial landscape: updated regulations are now in force
The Health Research Authority (HRA) and the Medicines and Healthcare products Regulatory Agency (MHRA) have introduced the largest package of clinical trial regulatory reforms in over 20 years.
The updated regulations are designed to protect trial participants, strengthen patient safety, and accelerate approvals by reducing unnecessary burdens on researchers, to support high-quality, trusted research taking place in the UK.
Feedback from a public consultation in 2022 helped shape the proposals to improve how clinical trials of investigational medicinal products (CTIMPs) were run in the UK.
Working in partnership, the HRA and MHRA sought the views of patients, researchers, healthcare professionals and industry to inform and develop the new framework.
The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 were signed into law in April 2025.
Following a 12-month implementation period, the regulations came into force on 28 April 2026.
Who these changes affect
The updated regulations impact everyone involved in CTIMPs in the UK:
- researchers and sponsors
- Research Ethics Committees (RECs)
- trial participants and the public
- healthcare professionals
Why these changes matter
The reforms:
- align the process for the MHRA and RECs to review and approve applications and modifications
- enhance transparency and accountability for research findings
- reduce unnecessary burdens while upholding ethical and safety standards
Together, these improvements are designed to strengthen the UK's position as a global leader in clinical research.
Key changes in the regulations
The following areas of the regulations have been updated.
New and updated definitions
The term ‘amendment’ to describe changes to approved trials has been replaced with ‘modification’. This term is already used by European Union nations to describe changes to CTIMPs. This change makes sure there is better alignment between the UK and the international research community.
Modifications are now categorised as ‘substantial modifications’, ‘modification of an important detail’ or ‘minor modifications’.
The updated regulations have introduced new definitions including ‘non-investigational medicinal product’, ‘notifiable trial’ and ‘public registry’.
There have also been changes to existing definitions including the removal of the term ‘authorised health care professional’. Instead, the updated regulations say that chief investigators and investigators should be a health care professional as defined in the amended legislation.
The updated regulations also replace the term ‘subject’ with ‘participant’ and ‘trial site’ with ‘trial location’.
The approvals process for clinical trials
Excerpt from the official page. The original is authoritative. Continue reading at UK Health Research Authority ↗