Supporting the use of replacement approaches in regulatory safety assessment – delivering the Government’s strategy on replacing animals in science

Developed with input from the NC3Rs cross-sector expert Regulatory Sciences Forum, the resource is a database listing replacement methods and approaches that can be used to generate data for decision-making under UK medicines and chemicals regulations. It delivers a key part of Commitment 10 – Publish regulatory agency accepted alternative methods and priorities for future development and validation – in the UK Government's Replacing Animals in Science strategy which was published in November 2025.

The list includes methods and approaches that have been formally validated through internationally recognised processes, such as Organisation for Economic Cooperation and Development (OECD) test guidelines, as well as approaches that are already referenced in regulatory guidance. Covering a range of human health and environmental safety endpoints, the resource also signposts users to supporting guidance and additional sources of information.

By bringing together examples of methods and approaches with potential regulatory applicability, the list will make it easier to identify where alternatives to traditional animal toxicity tests can be used. Increasing the use of data generated from replacement approaches in regulatory submissions will help build confidence in these methods and support their wider adoption.

The list is initially being published as an Excel spreadsheet to enable consultation. The list will then be transferred into a database on the NC3Rs website to improve ease of access. The database will be updated over time as new methods and approaches emerge and regulatory requirements evolve. Input from the sector will be sought as part of this process.

"The database has been developed to help scientists, safety assessors and regulatory specialists navigate the rapidly evolving landscape of replacement methods and approaches. By bringing together examples of methods with potential applicability under UK regulatory frameworks, we aim to make it easier to identify opportunities to generate toxicity data without the use of animals.

This is the first step in what will be an evolving resource. Future updates will provide additional regulatory context on how these approaches may be considered and applied within specific UK assessment frameworks."

Dr Natalie Burden
Head of New Approach Methodologies (NAMs) Strategy at the NC3Rs