Using Animals for Testing: Pros Versus Cons

By: Ian Murnaghan BSc (hons), MSc - Updated: 28 Nov 2025 | *Discuss

 

Animal testing has long been a subject of debate, with both advantages and disadvantages. Neither side offers a definitive solution that satisfies the public, governments, or the scientific community.

Pros or Positives of Animal Testing

2. Improves human health:
This is why many scientists and members of the public continue to support its use—particularly in medicine. While some strongly oppose testing for cosmetics, many still agree that it is necessary for creating new treatments for serious illnesses.

3. Helps ensure the safety of drugs:
Animal testing provides an early safeguard before human trials begin. Because some drugs can cause severe harm, testing on animals first reduces risks and saves human lives. In addition, medicines proven safe through these tests often go on to extend and improve quality of life.

4. Alternatives cannot yet fully replicate human biology:
Although new testing technologies are emerging, they do not yet simulate the complexity of the human body. Animals are still considered the closest match, offering researchers valuable insights that alternative methods cannot currently replace.

Cons or Negatives of Animal Testing

2. Some testing produces no practical benefit:
A significant number of substances tested never reach approval or public use. Critics argue this means animals may suffer or die without any direct benefit to humans, making the process seem wasteful and ethically questionable.

3. It is very expensive:
Animal testing is costly. Beyond buying animals, expenses include food, housing, care, and repeated experiments that may run for months or even years. Entire industries exist to breed animals specifically for research, which adds to the financial burden.

4. Animal results are not always reliable for humans:
Animal biology is not identical to human biology. Drugs may act differently in humans than in animals, raising concerns about reliability. Stress and unnatural lab conditions may also affect animal responses, weakening the accuracy of results.

Personal Choice

Legislation & Regulation

• European Union – Directive 2010/63/EU on the protection of animals used for scientific purposes:
This is the principal EU law on animal research. It mandates high standards of welfare, requires justification of animal use, and enshrines the principle of the 3Rs (Replacement, Reduction, Refinement). It also extended protections to foetal forms of mammals (in the last third of development) and to cephalopods. Member States must report annually on numbers of animals used and the severity of procedures. In addition, the EU has banned animal testing for cosmetics: testing of finished cosmetic products has been banned since 2004, and testing of cosmetic ingredients since 2009, with a marketing ban on cosmetics tested on animals since 2013.

• Council of Europe – European Convention for the Protection of Vertebrate Animals:
Adopted in 1986, this convention (often called the “animal experimentation convention”) sets standards for the humane use of vertebrates in scientific research. It influenced later EU legislation.

• United States – Animal Welfare Act (AWA):
The AWA is the main federal statute regulating the treatment of animals in research, testing, and exhibition in the U.S. It sets minimum standards for housing, feeding, veterinary care, handling, transport and oversight by Institutional Animal Care and Use Committees (IACUCs). However, certain animals commonly used in research—such as rats and mice bred for research—are excluded under the AWA. Facilities that violate the AWA may incur fines or lose licenses.

• Emerging legislation:
In the EU, the European Commission has launched a “Roadmap Towards Phasing Out Animal Testing” in chemical assessments. In the U.S., bills such as the KITTEN Act and the AFTER Act seek to further limit harmful practices and ensure adoption of lab animals after experiments.

For more information about the ethics of animal testing on this site, read the following features:

1. The controversy of animal testing
2. Medical treatments that have been found as a result of animal testing
3. Medical trials on humans.

External Resources

The BBC education page on animal ethics

The Government legislation relating to animal testing

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