News

Published: 05 August 2025

A new scientific publication co-authored by Dr Katy Taylor and Dr Dilyana Filipova, both with ECEAE affiliations, sheds light on the persistent use of animal testing for botulinum neurotoxin (commonly known as Botox), despite the availability of modern non-animal methods. The paper, authored under the SAFE consortium (Safety Assessment Through Animal Free Evolution) in the Netherlands, marks a significant European collaboration to accelerate the shift toward safety science that does not rely on animal experiments.

Botulinum neurotoxin (BoNT) is widely used for both cosmetic purposes and medical treatments. However, every batch released to the market has traditionally been tested for safety using the controversial LD50 test, where groups of mice are injected with the toxin at various concentrations to determine the lethal dose that kills half of them. These LD50 tests are also performed at multiple stages throughout BoNT production. The process is extremely distressing: every year, hundreds of thousands of mice in Europe experience cruel and painful deaths, often while fully conscious. This continues despite the existence of validated, non-animal, human-relevant cell-based tests.

ECEAE’s campaign: Fighting for change

Since 2009, the European Coalition to End Animal Experiments (ECEAE) has spearheaded a high-profile campaign to stop this needless animal suffering (1). In 2019, Dr Katy Taylor and Dr Corina Gericke have published a scientific paper that has influenced the scientific and regulatory debate (2). Through public outreach, policy advocacy, petitions, and working with manufacturers and regulators, ECEAE has contributed to industry change: many major companies have adopted non-animal methods for most of their BoNT batch testing. 

As part of this effort, ECEAE collected more than 164,000 signatures from concerned citizens across Europe and formally submitted them to the European Medicines Agency (EMA), sending a powerful message that the public demands an end to animal testing for Botox. Nonetheless, regulatory inertia and slow uptake mean that it is estimated more than 200,000 mice are still used annually for such testing in Europe.

ECEAE’s message remains unequivocal: it is time for all animal testing for Botox / BoNT to end. ECEAE demands the outdated mouse LD50 test be removed from the European Pharmacopoeia and replaced with the mandatory use of human-relevant, cell-based tests. Continued use of animal-based tests is both scientifically and ethically indefensible when modern non-animal methods exist.

New evidence: Highlights from the SAFE publication

The new publication – part of the work of SAFE consortium – provides a comprehensive update on the transition to non-animal testing methods (NAMs) for BoNT safety testing in Europe, a key global producer of these products (3).

By analysing publicly available Non-Technical Summaries (NTSs) from testing facilities in the UK, Germany, and Ireland, the paper estimates annual mouse use for BoNT testing and reveals the following insights:

• While Germany has likely recently phased out the LD50 tests for BoNT products, such tests persist in the UK and Ireland.
• Even when companies have developed validated cell-based assays (CBAs), the LD50 test continues to be used for certain purposes such as reference standard testing, validation of CBAs, lack of universally accepted non-animal methods, and to meet regulations for market authorization of new BoNT products.
• Overall, human-relevant non-animal methods are recognized by authorities but their adoption across countries and companies remains inconsistent and slow.
• Regulatory reluctance, differing interpretations of legal requirements, and commercial hesitation further delay full transition.
• Crucially, the study found that accurately estimating the precise number of mice used is challenging due to limited transparency and the severity of the LD50 test, emphasizing the urgent need for improved openness about animal use in high-severity procedures.

The paper strongly argues for removing the mouse LD50 test from the European Pharmacopoeia and making human-relevant, cell-based assays the legal standard for BoNT testing. It also outlines important next steps including harmonizing regulatory practices across Europe, providing clearer timelines, and offering better support for manufacturers to transition successfully.

Looking Forward

The advocacy and research by ECEAE and the SAFE consortium make it clear: animal testing for Botox is outdated and must end. ECEAE will continue to demand the removal of the mouse LD50 test from European standards and insist on up-to-date, human-relevant non-animal methods as the only acceptable testing approach.

This research represents a crucial step forward in replacing outdated animal tests with humane, scientifically advanced methods - reflecting our shared commitment to better, animal-free science.

References

1. ECEAE: Stop Botox animal testing, 23.4.2025 
2. Taylor K. et al. Botulinum toxin testing on animals is still a Europe-wide issue. ALTEX - Alternatives to animal experimentation 2019; 36(1):81–90
3. Watkins J.C. et al. Botulinum Neurotoxin: Tracking the Transition from Lethal Dose to In Vitro Models. NAM Journal 2025; doi: 10.1016/j.namjnl.2025.100040:100040