Alternatives to Animal Testing: The 3Rs in Practice

The 3Rs framework — Replace, Reduce, Refine — guides efforts to improve welfare in research animals, and new technologies are accelerating the replacement of animal models with human-relevant alternatives.

Key Facts

Approximately 3 million procedures were carried out on animals in UK research in 2022, down from 4 million in 2015
Organ-on-chip technology can replicate human organ function with greater predictive accuracy than many animal models
The US FDA has dropped the requirement for animal testing before human clinical trials in some drug categories
Netherlands has a national plan to phase out animal testing by 2025 (partial) using validated alternatives
Zebrafish larvae are used as a partial alternative to mice for many compound toxicity screening steps

Welfare Considerations

Research animals experience a range of welfare impacts from minimal (blood sampling, behavioural observation) to severe (surgical implantation, toxicity testing, cancer induction). The moral weight of this research use depends on its necessity: animal use in research that could be conducted with validated alternatives is increasingly indefensible both ethically and scientifically, since human-relevant alternatives often produce better predictive data. The acceleration of organ-on-chip, organoid and computational modelling technologies is rapidly expanding the toolkit for humane research.

What You Can Do

Support NC3Rs and the Fund for the Replacement of Animals in Medical Experiments (FRAME) financially
When receiving medical prescriptions, note that some companies are transitioning to alternative testing methods
Advocate for public research funding to prioritise alternatives development at equivalent levels to animal-use research
Engage with your institution's Animal Welfare and Ethical Review Body if you work in research
Support regulatory changes that accept validated alternatives as sufficient for regulatory approval purposes