# Clinical trials for medicines: International Council for Harmonisation (ICH) annotations

Source: https://www.keypedia.com/records/uk_mhra_guidance/uk-mhra/8162f0da-fde3-4f47-a784-ed9e5f9d0b6c
Type: Guidance
Published: January 12, 2026
Updated: April 27, 2026

> The Medicines and Healthcare products Regulatory Agency (MHRA) has announced that the amended Clinical Trials Regulations became fully effective on April 28, 2026. This transition marks the official implementation of these regulations, moving the associated guidance from draft status to active enforcement. The regulatory framework centers on the International Council for Harmonisation (ICH) Efficacy guidelines, which establish global standards for the design, safety, conduct, and reporting of clinical trials. While the ICH guidelines provide a broad international baseline, they frequently refer to 'applicable regulatory requirements' specific to individual regions. This guidance clarifies those requirements for clinical trial sponsors and investigators operating within the United Kingdom. It serves as a compliance bridge, identifying the specific UK laws and secondary guidance documents that fulfill the ICH mandates. As this is a general regulatory update rather than a specific enforcement action, no individual company name, inspection dates, or violations are identified in the text. Instead, the focus is on systemic compliance. Stakeholders are required to align their clinical trial operations with the newly effective 2026 regulations and consult the linked UK-specific resources to ensure adherence to international efficacy standards. This ensures that clinical research conducted in the UK meets high safety and quality benchmarks.

---

## Content

The amended Clinical Trials Regulations took full effect on 28 April 2026. As such, this guidance should now be considered effective and is no longer in draft. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) has produced a series of international guidelines concerning the design, conduct, safety and reporting of clinical trials (the Efficacy guidelines). In places, these guidelines include references to “applicable regulatory requirements” or similar in the relevant ICH region. The documents linked on this page are intended to support those involved in running clinical trials in the UK to comply with the ICH Efficacy guidelines by specifying what the applicable regulatory requirements or relevant guidance documents are for the UK.

## Attachments

- [UK-specific annotations to ICH E6(R3)](/government/publications/international-council-for-harmonisation-ich-e6r3-annotations/uk-specific-annotations-to-ich-e6r3)
- [UK-specific annotations to ICH E8](/government/publications/international-council-for-harmonisation-ich-e6r3-annotations/uk-specific-annotations-to-ich-e8)