Ending Animal Experimentation for Science

Ending Animal Experimentation for Science

Ethics and science can go hand and hand and when they do, we get to see science upheld to its fullest integrity.

When animals are used in experiments aimed at trying to predict how humans will respond, the findings are fundamentally flawed. We shouldn’t be wasting time, money, and other resources on bad science like this - it will only ever yield poor data!

Ending animal experimentation would benefit science in many ways…


1. Animal experiments are expensive and take a long time

Keeping, breeding, and testing on animals is incredibly expensive.1

  • The cost of developing a new drug (which includes everything from the research stage to obtaining approval) costs approximately 1.5 billion USD (~ 2.4 billion NZD).2
  • In addition to standard research costs, research on animals requires animal care staff, training and management of staff, veterinary care, maintenance (i.e., of cages and equipment), animal food and bedding (and enrichment, if they’re lucky), environmental control (like room temperature, ventilation and light regime) and animal acquisition (maintaining breeding colonies or buying animals) for the research required.
  • Transgenic animals can be especially expensive and often have to be purchased from overseas. For example, an experiment that was conducted in NZ and published in 2022,4 involved the use of transgenic mice. Each mouse cost 140 USD (~ 220 NZD).5 

Conducting animal experiments takes a long time.

  • The time it takes to develop one drug (including both animal and human trials) can range between 3.8 and 14.4 years.6
  • Not only are they expensive, but many transgenic animals have special needs or need to be bred first, which can take time before they are even shipped.7


2. Animal experiments have a high variation and publications are often biased

The results of animal experiments vary a lot.

  • Rodent experiments for toxicology (studying the adverse effects of substances) were found to agree between two databases a mere 57% of the time.8
  • Growing evidence indicates that the current standard practices of housing and care in laboratory animals are associated with abnormal brain9 and behavioural development10 and other signs of poor welfare,11 which may also compromise the scientific validity of research findings.
  • Environmental enrichment alone can decrease the drug-seeking behaviour of rats being accustomed to heroin12 and cocaine.13
  • Even high standardisation can’t ensure reproducible results, and might even make matters worse.14

The validity of animal studies is increasingly questioned.

  • Animal-based research is commonly overstated in media, often prematurely implying ‘breakthroughs’ and thereby hurting the credibility of scientific work.15
  • When published research is later found to have faults in the study design or execution, research becomes unreliable.16
  • Animal models have never been properly validated! Attempts have been rare and failed to prove their usefulness in advancing human medicine.17
  • Negative results are published less often, producing bias and false expectations.18 Currently animal studies do not have the be preregistered, meaning animal experiments can be conducted and the findings are never shared. This will be more likely with experiments that do not produce a favourable result. We do not know how many fruitless animal experiments have been repeated by different researchers (on different animals) over the years. 
  • Experiments giving rats a proper environment and the choice between drugs and social interaction with other rats proved that the drug-seeking of earlier studies was mainly driven by social isolation and empty cages. Drug addiction was perceived as wrong for decades because of studying the behaviour of isolated sad rats and non-human primates.19


3. Animal-free methods are often cheaper and more accurate

Animal-free laboratory material has advantages.

  • Animal-free production of antibodies (proteins that trigger certain immune reactions and are vital for many laboratory methods) results in better antibodies. They are of higher quality, have more parameter selection20 and less initial material is needed to produce them (faster).21 Traditionally, animals (often sheep or rabbits) are used and injected with antigens to harvest the antibodies their immune system produces.
  • Cell culture needs to grow in a medium. For many applications, the animal-free medium has superior properties22 and far less variation23 than traditionally used foetal calf serum.

Animal-free test methods have advantages.

  • Animal-free methods to test chemicals for skin or eye irritation outperform the tests that are traditionally done on rabbits.24
  • Toxin testing in shellfish via mass-spectrometry has had better accuracy than the mouse assay (a cruel animal test on mice) for a long time.25
  • Human Liver-Chips caught 87% of liver-toxic drugs that had previously passed animal testing. Based on this, Organ-Chips could generate over $3 billion USD (~ 4.8 billion NZD) annually for the pharmaceutical industry through increased research and development productivity.26


4. Animal-free methods open up new research opportunities that aren't possible with animal experiments

  • The tissue on Organ-Chips can be observed via live imaging in real-time.27
  • Organ-Chips allow for tissue-specific non-invasive sampling during the observed processes.
  • Organ-Chips enable researchers to control every aspect of the microenvironment.28
  • They also allow researchers to compare the reactions of the same person to different treatments.29
  • Gut-Chips allow for a long-term anaerobic culture of human gut microbes (which is not possible in animals).30
  • Brain-Chips can recreate reactions to chemotherapy for individual patients (i.e., decrease resistance or aggressive growth of the same kind of tumour).31
  • Placenta-Chips provide a highly controllable, dynamic microenvironment and permit the observation of cellular interactions and behaviour in real time.32
  • The severity of the lack of oxygen can be adjusted and monitored in Organ-Chips (this plays a role in how cancer tissue reacts to treatment.)33



  • Return to the Benefits of Ending Animal Experimentation homepage.
  • Find out more about the benefits for animals.
  • Find out more about the benefits for people.



  1. https://www.ohe.org/publications/rd-cost-new-medicine
  2. https://www.ohe.org/publications/rd-cost-new-medicine
  3. https://doi.org/10.17226/10006
  4. https://doi.org/10.1186/s40478-022-01347-2
  5. https://www.mmrrc.org/catalog/sds.php?mmrrc_id=34832
  6. https://doi.org/10.1001/jama.2020.1166
  7. https://www.jax.org/jax-mice-and-services/colony-management/breeding
  8. https://doi.org/10.1289/ehp.01109509
  9. https://doi.org/10.1016/s0166-2236(00)01718-5
  10. https://doi.org/10.1093/ilar.46.2.106
  11. https://doi.org/10.1038/35089208
  12. https://doi.org/10.1016/j.drugalcdep.2021.108852
  13. https://doi.org/10.1111/adb.12581
  14. https://doi.org/10.1038/nmeth.1312
  15. http://doi.org/10.1136/bmjos-2019-100039
  16. https://doi.org/10.1371/journal.pmed.0020124
  17. https://doi.org/10.1258/jrsm.2007.070164
  18. https://doi.org/10.1038/d41586-019-02674-6 
  19. https://doi.org/10.1111/add.14481
  20. https://doi.org/10.1016/j.tibtech.2010.05.001
  21. https://doi.org/10.1002/pmic.200500579
  22. https://doi.org/10.1016/j.jcyt.2015.08.002
  23. https://doi.org/10.14573/altex.1605021
  24. https://doi.org/10.1016/j.toxlet.2018.03.006
  25. https://doi.org/10.1016/0041-0101(94)90410-3
  26. https://doi.org/10.1038/s43856-022-00209-1
  27. https://doi.org/10.1016/j.jcmgh.2019.11.008
  28. https://doi.org/10.7554/eLife.46188
  29. https://doi.org/10.1016/j.cels.2016.10.003
  30. https://doi.org/10.1038/s41551-019-0397-0
  31. https://doi.org/10.1038/s41551-019-0363-x
  32. https://doi.org/10.1007/s00018-022-04648-w
  33. https://doi.org/10.1021/acsbiomaterials.2c00207