Non-animal test can save thousands of mice
We welcome the news from the European Directorate for the Quality of Medicines and Healthcare’s (EDQM) that they will work to phase out the use of the mouse lethal dose 50 (LD50) test for checking the potency of botulinum toxin (Botox) products.
The European Pharmacopoeia Commission agreed in June to restart its Botulinum Toxin Working Party as a step towards removing this cruel test from the EU’s ‘rulebook’ for medicines safety, the European Pharmacopoeia.
This follows the EDQM’s removal of the rabbit pyrogen test from the European Pharmacopoeia in January 2026, a move which is expected to bring a sharp drop in the use of the rabbit test for the quality control testing of medicines in the EU and UK.
The EDQM sets legal standards for medicines and public health in Europe, and is part of the Council of Europe, an organisation which protects human rights across 46 countries.
The LD50 test identifies the dose of a substance that is required to kill 50% of the animals used in the test. Mice have the botulinum toxin injected into their abdomens and, over three days, become increasingly paralysed by it. If left, mice in the higher dose groups will stop being able to breathe and suffocate to death. Approximately 50% of the mice die per test, and survivors are killed at the end of the test.
A cell-based test to replace the LD50 animal test has been available and accepted for regulatory use for many years. While a number of the major manufacturers of Botox products have transitioned to the use of the non-animal approach, this severe animal test continues for the routine batch testing of Botox products.
According to the most recently published EU statistics for the year 2023, 164,802 mice were used for batch potency testing of human medicines, most of which we believe to be for the testing of Botox products. This is an 8% increase on uses reported for 2022.
The testing of Botox products is one of the ten animal experiments featured in our Replace Animal Tests (RAT) List, which we created over a decade ago to highlight tests which already have approved non-animal replacements.
Changes to the European Pharmacopoeia extend beyond the EU. The UK remains a member of the Council of Europe, meaning that a removal of the mouse test from the Pharmacopoeia will take effect in the UK as well as the EU.
Our Director of Science and Regulatory Affairs, Dr Emma Grange, said: “These efforts align with commitments made in the recently published UK strategy, Replacing animals in science, to end the use of animals for the batch potency testing of Botox products by the end of 2027. We fully support the EDQM’s efforts and look forward to the phase-out of this severe animal test without delay.”
Published on 19 August, 2026.
