chevron-down Created with Sketch Beta.
February 27, 2023 Legislative Update

Reducing and Replacing Animals Used in Research and Testing

By Molly Armus

Every year, an estimated 192.1 million animals are used in experiments worldwide. In the United States alone, it is estimated that more than 50 million animals are used in research, including tens of thousands of primates, dogs, cats, and even more mice and rats. Their purposes vary—from animals being infected with certain diseases to see how they would affect humans to being force-fed chemicals and drugs to determine their potential harm. Yet, animal experiments are often unreliable predictors of human safety. According to the Food and Drug Administration (FDA), just 8 percent of drugs tested on animals are deemed safe and effective for human use because different species can respond differently when exposed to the same chemicals, drugs, and treatments.

Recently, a flurry of bipartisan legislation has been introduced to achieve the first two principles of the Three Rs—replacement, reduction, and refinement—an ethical framework developed in the 1960s to guide the use of animals in research and testing. “Replacement” refers to avoiding the use of animals where they otherwise would have been used, “reduction” refers to using as few animals as possible, and “refinement” refers to causing as little suffering to animals as possible wherever feasible.

Development of Non-Animal Test Methods

Technology continues to evolve, and significant advances have been made to increase non-animal options for research and testing. For example, “organs-on-chips” have been developed, which are tiny 3D chips created from human cells that look and function like miniature human organs to determine how human systems respond to different drugs or chemicals and to find out precisely what happens during infection or disease. Researchers have also used a combination of human cell-based tests and sophisticated computer models to deliver human-relevant results.

However, policy changes are still needed, primarily because there is no legal requirement at the federal level that researchers consider—and use, if available—a non-animal alternative. The Animal Welfare Act, the federal law governing the care and use of laboratory animals in the United States, requires a researcher to demonstrate why there is no alternative to the research on animals. Yet, this is limited to tests that cause pain and distress to the animals used. Moreover, developing and having a non-animal alternative validated is a complex, lengthy process that faces the additional challenge of inadequate funding.

Pending Legislation and Recent Policy Changes

The FDA Modernization Act 2.0 was introduced and passed by the Senate in September 2022. S. 5002 authorizes the use of specific alternatives to animal testing, such as computer models, to obtain an exemption from the FDA to investigate the safety and effectiveness of a drug. It also removes a requirement to use animal studies to obtain a license for a biological product that is similar or interchangeable with another biological product. It now awaits consideration by the House of Representatives.

Another significant piece of legislation is the Humane and Existing Alternatives in Research and Testing Sciences (HEARTS) Act. H.R. 4101 will amend the Public Health Service Act to expand the National Institutes of Health’s (NIH) responsibility to promote non-animal research and testing methods in experiments. The bill also requires that NIH applications for research grants involving animals include an assurance that non-animal methods for such research are not available. It has been referred to the House Energy and Commerce Committee.

The Humane Cosmetics Act is another bill introduced during this congressional session. S.3357/H.R. 6207 has been introduced multiple times before and will end the testing of cosmetic products on animals and prohibit the sale of products developed using animal testing. Interestingly, besides having bipartisan support, the Personal Care Products Council, the leading national trade association representing cosmetic and personal care products companies, has endorsed this bill.


As increasing numbers of people find animal research unethical and non-animal test methods continue to progress and improve, there is going to be an even greater push to reduce and replace the use of animals in experiments. Particularly because when this type of legislation passed, it resulted in real change at the federal agency level: in 2016, the Frank R. Lautenberg Chemical Safety for the 21st Century Act was signed into law. It requires chemical companies and the Environmental Protection Agency (EPA) to replace and reduce animal tests. As a result, in 2019, the EPA announced that it would stop conducting or funding studies on mammals by 2035. It also announced that it would focus on developing and using New Approach Methods (NAMs) to test chemicals for health effects.

Ultimately, we need more bipartisan legislation to continue to move forward to ensure that both federal agencies and research entities do more to end the use of animals in research and testing.

The material in all ABA publications is copyrighted and may be reprinted by permission only. Request reprint permission here.

By Molly Armus

Molly Armus is the Virginia State Director for the Humane Society of the United States. In this role, she advances stronger animal protection laws and policies through grassroots organizing and direct lobbying efforts. Molly is currently the Membership Vice-Chair of the TIPS Animal Law Committee and Co-Chair of the Policy and Alliances Subcommittee. She may be reached at [email protected].