Replacing animal testing in the UK

Summary

• Animal testing means using living animals in research, medicine development and safety checks. In Great Britain it is licensed under the Animals (Scientific Procedures) Act 1986.
• The dispute is over how many animals are needed and how fast alternatives can replace them. Animal welfare groups say progress is too slow. Understanding Animal Research says some questions still need whole animals, as cells and computer models cannot yet show how a whole body responds.
• The guiding principle is the 3Rs: replace animals where possible, reduce the numbers used, and refine procedures to cut suffering.
• In April 2025 the US Food and Drug Administration (FDA) said its animal testing requirements for monoclonal antibodies and other drugs would be reduced, refined or potentially replaced. It would lean on computer models and organoids, small lab grown tissue models.
• On 11 November 2025 the UK published "Replacing animals in science", with £75 million of headline funding. Its first target, to end regulatory skin and eye irritation tests on animals by the end of 2026, is framed as an aim.
• The Home Office, which licenses the work, reported 2.54 million procedures in 2025. That is down from 2.64 million in 2024, yet experimental procedures rose for dogs (9%), primates (15%) and birds (14%).

Dig deeper

• The later target runs to 2030. By then the government aims to cut dog and primate use in dedicated pharmacokinetic studies, which measure how the body absorbs, spreads and clears a drug, by at least 35%.
• The government also accepts limits. Its strategy says that "some animal research will continue, due to the maturity of alternatives available".
• Christian Maass, a computational biologist whose company builds computer models of drug outcomes, wants alternatives tested head to head against animal models. He says researchers have not yet provided "the evidence and the proof that we are doing better or as good as the animal models".
• On 21 September 2026 the FDA issued a direct final rule replacing "animal tests" with "nonclinical tests". The agency says the rule "does not eliminate or prohibit animal studies". It takes effect on 4 February 2027 unless significant adverse comments arrive by 7 December 2026.
• The same question, whether animal evidence is enough before people are dosed, arose in AI Vaccine Trial.

Ethical issues

Interview questions

• What do you know about the 3Rs, and what does each one ask a researcher to do?
• What happened when the UK government published its strategy in November 2025?
• What do you know about the Home Office figures for 2025, and why do the totals hide the rise in some species?
• You are a junior researcher and you see a colleague repeating a dog study that a validated computer model could now replace. What do you do?
• What happened when the FDA announced its plan in April 2025?
• Researchers say some questions still need whole animals, and welfare groups say the pace is too slow. What is the strongest argument on each side, and where do they actually disagree?
• What do you know about how the Animals (Scientific Procedures) Act 1986 licenses research?