Overview
Animal use in science is a complex field that invokes expertise from both lawyers and scientists. Reliance on animal models in scientific endeavors stems, in part, from a mandate to end unethical human-subject research while still ensuring product safety before use by the public, known as The Belmont Report. But this was not the start of animal experimentation, which dates back hundreds of years.
As we look to the future, there is a growing recognition across geopolitical borders of both a scientific and an ethical need to move away from animal experimentation. Although animal models have provided helpful information about many products regularly used today, there remains an insurmountable biological translation issue between non-human animals and humans. Further, politicians, the public, and even scientists are increasingly voicing concerns regarding the ethics of animal research. From concerns around confinement to the expression of natural behaviors, the use of animals as research subjects has been fraught. New Approach Methods (sometimes referred to as “non-animal models” or NAMs) help to address both of these issues. They provide a path forward where increasingly fewer animals are needed to ensure product safety, and they address the translation issue by yielding human-relevant data.
The following is a brief introduction to the field of Animal Research. It will provide a framework to better understand the current laws around animal testing and research. It will also provide links for those who want to dive deeper into a particular topic. This content is focused largely on US-based laws. While it may refer to other jurisdictions for the purpose of comparison, it does not aim to provide a robust explanation of the laws for jurisdictions outside the United States.
Note: There are different types of laws that are relevant to this field. Two of the most important types are (1) laws that promote animal welfare and (2) laws that promote the development and use of NAMs. Both types of laws relate to the use of animals in testing and research, and both aim to improve both scientific outcomes as well as animal wellbeing. However, they are distinct. As you read through the material below, keep this distinction in mind.
Types of Animal Use in Science
Oversight for animal research in the US is largely provided by federal law. While there are federal laws that broadly seek to ensure minimum welfare standards when animals are used in research and testing, there are also federal laws that either mandate or encourage the use of animal models when seeking regulatory approval. For more information on the laws that dictate minimum welfare standards, see the section below. This section will discuss the oversight structure when animal use is encouraged or mandated for regulatory approval.
Basic Research (NIH)
Federal law does not generally require researchers to use animal models as a condition of receiving funding from the National Institutes of Health (NIH). Instead, the relevant statutes establish requirements that apply when an investigator elects to use animals and influences how animal studies must be designed.
The Health Research Extension Act of 1985 directs NIH to establish standards governing the care and treatment of animals used in federally funded biomedical research. The law requires institutional oversight and training, concerning both humane animal experimentation and methods that limit animal use or distress. While it regulates animal research, the Act does not require researchers to conduct animal studies or establish animal testing as a prerequisite for NIH funding.
The 21st Century Cures Act is another statute that impacts the design of certain NIH-funded basic research. Section 2038 of the Act requires NIH to develop policies addressing relevant biological variables in basic research. The statute specifically addresses how differences in male and female cells, tissues, and animals should be examined and analyzed. NIH implemented this direction through its Sex as a Biological Variable policy, under which researchers proposing vertebrate animal studies generally must account for sex in the research design or provide justification for the use of only one sex. While this policy may increase the number of animals used in a study that already relies on animal models, it does not require researchers to select an animal model as their basis for their proposed study.
In addition to these statutes, NIH grant procedures also focus on regulating rather than mandating animal use. When live vertebrate animals are proposed for a study, the applicant must submit a Vertebrate Animal Section form, explaining why the selected species is appropriate for a submitted study and why the objectives of the research cannot be accomplished using a non-animal or invertebrate model.
Recently, NIH policy has increasingly favored model-neutral and human-relevant research. In June 2025, NIH launched the Office of Research Innovation, Validation, and Application (ORIVA) with the intention of coordinating efforts to develop, scale, and validate the use of human-based approaches throughout NIH biomedical research. Additionally, in July 2025, NIH stated that it will not develop new funding opportunities exclusively supporting animal models or prescribe the type of model investigators must use.
Chemical Safety (EPA)
The Environmental Protection Agency (EPA) administers multiple federal statutes governing chemical safety. Whether those statutes require or encourage animal testing depends largely on the type of chemical product involved. Industrial chemicals are governed by the Toxic Substances Control Act (TSCA), while pesticides are subject to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).
Industrial Chemicals under TSCA
The Toxic Substances Control Act establishes a premanufacture-review process where manufacturers must generally notify the EPA before manufacturing or importing a new chemical. Manufacturers must also provide existing health and environmental information in their possession, or reasonably available to them, about the chemical. However, TSCA does not establish a minimum testing dataset for new chemicals to satisfy.
TSCA does, however, expressly directs EPA to reduce and replace vertebrate-animal testing to the extent practicable and scientifically justified. Section 4(h) requires EPA to promote alternative test methods and strategies that avoid new vertebrate-animal testing. EPA has accordingly adopted a preference for tiered testing, with non-vertebrate methods, computational models, and other new approach methods before higher-tier vertebrate studies are required.
Accordingly, TSCA does not generally mandate animal models as a prerequisite for placing industrial chemicals into commerce. Animal testing may be required on a case-by-case basis when EPA determines that necessary information cannot be obtained another way, but the statute directs the agency and manufacturers to avoid or minimize vertebrate testing whenever appropriate alternatives are available.
Pesticides under FIFRA
The Federal Insecticide, Fungicide, and Rodenticide Act requires pesticides sold or distributed in the United States to be registered with EPA. Before granting registration, EPA must determine that the pesticide will not generally cause unreasonable adverse effects on human health or the environment when used according to its approved labeling. Additionally, pesticides used on food or animal feed must also satisfy safety standards set under the Federal Food, Drug, and Cosmetic Act.
EPA’s pesticide data regulations, specifically 40 C.F.R. Part 158, identify studies that are required or conditionally required for different products and uses. These requirements include studies like dermal, carcinogenicity, and inhalation toxicity testing. EPA may also require ecological studies involving birds, fish, and other nontarget organisms. These requirements effectively operate as an animal-testing mandate in situations where a registrant must provide a particular safety endpoint, and no accepted non-animal method or existing data source is sufficient.
Cosmetic Safety (FDA)
Federal law does not generally require animal testing for cosmetic products or ingredients. With the exemption of color additives, cosmetics are not subject to premarket approval by the FDA, and manufacturers are responsible for ensuring that cosmetic products are safe before entering the market. The FDA expressly states that the Federal Food Drug and Cosmetics Act does not require the use of animals to establish the safety of cosmetic products.
The Modernization of Cosmetics Regulation Act of 2022 (MoCRA) strengthened existing safety obligations by requiring the “responsible person" for a cosmetic product to ensure and maintain records demonstrating “adequate substantiation of the safety of their cosmetic products.” FDA describes adequate substantiation as relying on supporting data that is “derived from scientifically robust methods.” However, MoCRA does not prescribe a specific testing method or require animal testing. FDA specifically notes that manufacturers are not required to conduct animal testing and that they may rely on existing safety data to support their products' safety.
While animal testing is not required under FDA regulations, FDA advises manufacturers to use the appropriate testing to effectively establish the safety of their ingredients and finished products. Where existing toxicological information or alternative methods are insufficient, a manufacturer may determine that an animal study is necessary to address a particular safety concern.
Recent FDA policies have expressly supported reducing reliance on animals. The agency encourages manufacturers to consider valid alternatives before conducting whole-animal studies and supports the development and use of methods intended to replace, reduce, or refine animal testing. When animal studies are used, FDA advocates obtaining the necessary scientific information from the minimum number of animals and using the most humane methods scientifically available.
Drug Safety and Efficacy (FDA)
Drugs, Medical Devices, Biologics, and Cell Therapy products are required to receive approval from the Food and Drug Administration (FDA) before being made available to on the market. The FDA’s authority for this oversight comes from the Federal Food, Drug, and Cosmetic Act (FFDCA). Before a product can be tested in human subjects, a company must receive clearance from the FDA. This clearance is typically predicated on a showing that the product is likely to be safe in humans and that the product’s effectiveness is scientifically sound. Once this clearance is received, the company can start human clinical trials. Everything before this is considered pre-clinical or sometimes referred to as “non-clinical.”
Nothing in the FFDCA requires a company to provide data from animal subjects. However, there has been a long history of FDA interpreting statutory language to require animal-based data. As a result, some regulations and guidance documents do require animal testing information to receive clearance to begin clinical trials.
In an effort to combat this unwritten policy, the FDA Modernization Act 2.0 was introduced and enacted in 2023 via the Consolidated Appropriations Act of 2023. This legislation amended section 505 of the FFDCA (21 U.S.C. 355) to make it clear that data from non-animal sources could suffice at the pre-clinical phase. The bill replaced “pre-clinical” with “non-clinical” and defined the term “non-clinical” to include:
[A] test conducted in vitro, in silico, or in chemico, or a nonhuman in vivo test, that occurs before or during the clinical trial phase of the investigation of the safety and effectiveness of a drug. Such test may include the following:
(1) Cell-based assays.
(2) Organ chips and microphysiological systems.
(3) Computer modeling.
(4) Other nonhuman or human biology-based test methods, such as bioprinting.
(5) Animal tests.
21 U.S.C. 355(z). Despite this statutory change, the FDA did not immediately update the relevant regulatory provisions, which gave rise to the FDA Modernization Act 3.0. This bill specifically identifies the relevant regulations that need to be amended to be consistent with the amended FFDCA. Since the introduction of this bill, the FDA has taken several steps to make clear their change in policy around animal testing. However, there remain several regulations out of step with the amended provision of the FFDCA. Therefore, the FDA Modernization Act 3.0 is anticipated to be enacted by the end of 2026.
Minimum Welfare Standards Under The Law
There are two principal federal frameworks that dictate minimum welfare standards when animals are used in research or testing. The most well-known is the Animal Welfare Act (AWA), which also governs welfare standards of animals in context outside of research and testing. The other, lesser-known provision, is the Public Health Services on Humane Care and Use of Laboratory Animals (also known as “The PHS Policy”). These laws are designed to work together, but each applies to a slightly different subset of scientific animal use. Because the PHS Policy does not currently require facilities to report on the number of animals used, it is unknown whether one covers a greater number of animals.
Animal Welfare Act (AWA)
The AWA was passed in 1966 and has gone through several revisions since. Although originally conceptualized as a law to protect companion animals from entering the animal research market as well as provide basic welfare mandates for animals used in research, it has since expanded in scope to cover not only animals used in research and testing but also animals used in entertainment and those breed for commercial purposes. There are two oversight mechanisms under AWA, which is enforced by the US Dept of Agriculture (USDA). Under the AWA, a covered entity can either be licensed by or registered with the agency. Research facilities are required to register with the USDA. Breeders and those who sell animals (in accordance with the AWA definition) for research purposes must be licensed by the USDA.
Both licensees and registrants are subject to inspection by the USDA, specifically the Animal and Plant Health Inspection Service (APHIS) subagency. In the case of a research facility, this inspection must occur at least annually. A licensee who fails to comply with the Act may be subject to loss of license, civil penalties up to $10,000 per offense, and criminal penalties up to 1 year in prison and up to $2,500 per offense. A registrant who fails to comply with the Act will be subject to a loss of funding where funding was provided by a federal agency.
The definition of “animal” under the AWA is very narrow. In addition to applying only to warm-blooded animals, it explicitly excludes “mice, rats, and birds bred for research purposes.” Unfortunately, the majority of animals used in research are purpose-bred mice and rats. Consequently, this means that the majority of animals used in research are excluded from the welfare mandates under the AWA.
The AWA does mandate research facilities form an internal review committee for research using animal subjects. This is the Internal Animal Care and Use Committee (IACUC). Under the AWA, IACUCs must review animal care spaces twice a year for compliance with AWA animal welfare regulations, review protocols that propose to use animal subjects, be available to facilitate inspections by USDA APHIS auditors, and submit an annual report with counts for the number of animals used in research.
PHS Policy
The Health Research Extension Act of 1985 amended the Public Health Services Act and directed the NIH to establish guidelines for the proper care and treatment of animals used in research, as well as requirements for the establishment of animal care committees. This mandate established the framework of the “Public Health Service Policy on Humane Care and Use of Laboratory Animals” or, more commonly, the “PHS Policy.”
The PHS Policy governs the use of live vertebrate animals in research and other activities conducted or funded by Public Health Service (PHS) agencies, Department of Health and Human Services (HHS), and institutions that have entered into an agreement with the NIH to follow the Policy. The PHS Policy operates as a system of federally enforced institutional responsibility, where an institution agrees to maintain a policy compliant animal care and use program with the NIH Office of Laboratory Animal Welfare (OLAW) responsible for overseeing the fulfillment of that commitment.
As part of this framework, an institution must maintain an Animal Welfare Assurance approved by OLAW. Through this Assurance, the institution formally commits to the PHS Policy requirements and agrees to maintain an appropriate care and use program. Once approved, an Assurance may remain valid for up to five years.
Coinciding with the Assurance, an institution must establish an Institutional Animal Care and Use Committee (IACUC), which serves as the local oversight body for animal research. The IACUC is responsible for reviewing and overseeing covered animal activities, evaluating the institution’s care and use program, and addressing compliance concerns. Institutions also maintain reporting obligations to OLAW, providing federal oversight of the institute’s compliance.
Overall, the PHS Policy establishes the institutional oversight framework that governs animal use in federally supported research. Its primary function is to ensure that institutions have systems in place to review and maintain appropriate standards for their care and use. Through the combined levels of assurance and oversight, the Policy is focused on creating an ongoing system of accountability for PHS supported animal research.
| AWA | PHS Policy |
Head of IACUC | Chief Executive Officer | Chief Executive Officer |
Min no. of committee members | 3 | 5 |
Frequency of onsite audits conducted by IACUC | Every 6 months | Every 6 months |
Frequency of humane care protocol review | Every 6 months | Every 6 months |
IACUC Protocol review | Initial; review every 3 years | Initial; significant protocol changes; review every 3 years |
State-Based Efforts
While the use of animals in science is highly regulated by the federal government, one would be remiss to discount the role of states in both ensuring the welfare of animal subjects as well as promoting the use of human-relevant non-animal methods. The role of states in this space has evolved over the years with an observed increase in popularity in recent years.
The JHU Tox Policy Lab’s research has identified eight categories of laws that implicate animal use in scientific research and/or new approach methods. These eight categories include: acquisition, cosmetic ban, disposition, licensing, NAM Utilization and Promotion, Records & Reporting, Restricted Testing, and Welfare.
The first identified law in this survey was passed in 1941 by Hawai’i when it was still a territory. Pound Seizure laws deal with the use of animals used in research when the animal was not purpose bred for scientific purposes. This stems from a history of pounds (known more commonly referred to today as “shelters”) providing unwanted dogs to research facilities for use in experimentation. States have taken different positions on this matter ranging from prohibiting the transfer, to permissively allowing the transfer, to mandating shelters facilitate the transfer. The law passed in 1941 by the Hawai’i legislature prohibited pounds from providing unclaimed and/or unwanted animals to research facilitates.
Another important milestone in the development of state law for lab-based animals comes from the Taub v. Maryland court case decided in 1983. This case is often misrepresented as holding that states are preempted from regulating the use of animals in research and testing. In reality, the holding of this case is much more narrow. The court held that the Maryland state legislature did not intend the state animal cruelty code to apply to “research activity under a federal program.” (“Accordingly, we do not believe the legislature intended section 59 of Article 27 to apply to this type of research activity under a federal program.” Taub v. State 463 A.2d 819, 822 (Md. 1983).) As a result of this case, many state animal cruelty laws have subsequently been amended to explicitly exempt research and medical facilities. This is one of many general exemptions (alongside, e.g., standard veterinary practices are also often exempt) observed in animal cruelty laws. However, states still retain the authority to regulate lab-based animal welfare. Currently, at least 30 states have enacted one or more laws related to the promotion of animal welfare for lab-based animals.
In the past ten years, there has been an explosion in lab-based animal laws passed at the state level. While most of these laws concerned animal testing bans for cosmetics and disposition of animals, one or more laws were passed in each of these categories. NAMs promotion remains the category with the fewest number of enacted laws. This may be a result of the relative newness of NAM technology or possible related to the slow rate of federal action. In the ten years following the passage of the Animal Welfare Act, five states passed a total of thirteen different lab-based animal laws. But has the 1941 Hawai’i law demonstrates, states need not wait for the federal government to take action.
International Authorities and Resources
Animal research and the development of New Approach Methods are also increasingly international issues. Regulatory standards developed outside the United States can influence the development, validation, and acceptance of testing methods domestically, particularly where industry stakeholders seek product approval across multiple nations. Several international authorities and initiatives are therefore relevant to understanding the broader landscape.
European Union
The European Union’s Directive 2010/63/EU on the protection of animals used for scientific purposes establishes minimum requirements governing animal research throughout EU Member States. Unlike the United States, where animal-welfare requirements are divided principally between the Animal Welfare Act and PHS Policy, the Directive establishes a broader framework built expressly based on the principles of Replacement, Reduction, and Refinement, commonly referred to as the 3Rs.
Under Article 4 of the Directive, Member States must ensure that, when possible, a “scientifically satisfactory method or testing strategy” that does not involve live animals is used instead of an animal procedure. Where an animal procedure remains necessary, the number used must be minimized, and the procedures must be refined to reduce any pain, suffering, or lasting harm.
The European Commission also operates the European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM). EURL ECVAM supports the development, validation, and standardization of non-animal methods and works to facilitate their acceptance for regulatory use. Its work includes validating alternative methods, coordinating lab networks, and sharing information relating to the 3Rs and non-animal approaches.
More broadly, the EU has also adopted explicit policy for transitioning away from animal testing. In June 2026, the European Commission published its Roadmap Towards Phasing Out Animal Testing for Chemical Safety Assessments. The roadmap establishes a long-term objective of gradually replacing animal testing for chemical safety assessments across EU regulatory frameworks and identifies focus areas spanning industrial chemicals, pharmaceuticals, medical devices, and other regulated products.
Organisation for Economic Co-operation and Development (OECD)
The Organisation for Economic Co-operation and Development (OECD) plays a different but particularly important role. The OECD is not a regulator comparable to FDA or EPA, and its Test Guidelines are not domestic law. Instead, the organization develops internationally harmonized testing standards that national regulatory authorities can incorporate or recognize within their own regulatory systems.
OECD also has Guidelines for the Testing of Chemicals that provide internationally recognized methods for evaluating potential effects of chemicals on human health. The Guidelines include both animal-based methods and non-animal approaches, and they are continually updated as methods develop.
For shared data collection, OECD has also implemented a Mutual Acceptance of Data (MAD) system. Under this system, qualifying data generated following OECD Test Guidelines can be accepted across participating jurisdictions, potentially reducing duplicative animal testing towards the same data.
For NAMs developers, OECD adoption can be particularly significant. Inclusion of a method within OECD Test Guidelines can provide an internationally recognized pathway for that method to be used across multiple jurisdictions rather than requiring individual acceptance of the method in every country.
National Programs of Note
In addition to the European Union’s regional framework, several countries have established national programs intended to advance the development, validation, and adoption of alternatives to animal testing. These programs vary in structure. Some focus primarily on the scientific validation of alternative methods, while others take a broader approach that incorporates research funding, policy, and government-wide strategies to reduce animal use.
United Kingdom
The National Centre for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs) was established in 2004 as the UK’s national organization dedicated to advancing the 3Rs. Its work includes funding the development of alternative technologies, supporting their adoption, and working with regulators and industry to incorporate 3Rs approaches into scientific and regulatory practice.
Recently, the UK government published its Replacing Animals in Science Strategy in November 2025. The strategy establishes a long-term objective of eliminating animal use in science and outlines the government's actions intended to accelerate the development, validation, and regulatory uptake of alternative methods.
Japan
Japan maintains the Japanese Center for the Validation of Alternative Methods (JaCVAM) within its National Institute of Health Sciences. JaCVAM was established to promote the use of alternative methods and advance 3Rs principles. JaCVAM evaluates the usefulness, limitations, and suitability of proposed alternatives and conducts validation studies when needed.
South Korea
South Korea operates the Korean Center for the Validation of Alternative Methods (KoCVAM) through the Ministry of Food and Drug Safety. KoCVAM supports the development and validation of alternative methods and promotes their implementation within Korea’s regulatory system. In 2026, the Ministry of Food and Drug Safety published procedures for a KoCVAM Validation Initiation Program, through which KoCVAM coordinates validation and provides technical support for animal-alternative methods developed in Korea with the goal of facilitating their use as internationally recognized regulatory methods.
Canada
Amendments to the Canadian Environmental Protection Act, 1999 (CEPA) recognize the need to replace, reduce, or refine vertebrate-animal testing when assessing potential risks posed by chemical substances. In July 2025, Health Canada and Environment and Climate Change Canada published a national strategy describing how agencies intend to develop and incorporate NAMs into chemical risk assessment under CEPA. Health Canada and Environment and Climate Change Canada also participate in the OECD Test Guidelines Program and other international projects focused on bringing new approaches into regulatory applications.
Brazil
Brazil has developed a national framework for promoting and recognizing alternatives to animal experimentation through the National Council for the Control of Animal Experimentation (CONCEA) and the National Network for Alternative Methods (RENAMA). CONCEA was created under Law No. 11,794 of 2008, which governs the scientific use of animals in Brazil and gives the Council responsibility for monitoring and evaluating techniques that replace animal use. RENAMA supports the development and implementation of alternative methods through a network of laboratories and researchers.
In 2025, Brazil also strengthened its legal commitment to alternatives like with Law No. 15,183 of 2025. This law prohibits the use of live vertebrate animals for testing cosmetics, personal-hygiene products, and certain associated ingredients, subject to some exemptions. Together, CONCEA, RENAMA, and the developing statutory requirements provide Brazil with a framework that links development, regulatory consideration, and a broader transition towards New Approach Methods.