The US Food and Drug Administration (FDA) is taking another step away from animal testing as the default in drug development, updating its regulations to explicitly recognize non-animal methods as acceptable options for generating safety evidence before products are tested in humans.
The agency issued a direct final rule on September 21, replacing references to “animal studies” across its regulations with broader terms “nonclinical tests” and “nonclinical studies.” The change removes language that could imply animal testing is the only acceptable route for generating safety information for drugs and biological products intended for human use.
Under the updated framework, developers can use New Approach Methodologies (NAMs), including human cell-based testing, organs-on-chips, computer modeling, and other emerging technologies where methods have been adequately validated and are appropriate for the product and regulatory question.
The rule does not ban animal testing or lower the evidence required by FDA. Animal studies can still be used where appropriate. Instead, the regulatory change gives developers greater flexibility over how they produce the evidence required to progress toward human clinical trials.
“This new rule supports the Trump Administration’s push to explore ways to complement, or where appropriate, replace animal studies with methods that may better predict how medicines will actually affect people,” said Acting FDA Commissioner Kyle Diamantas, JD, in a press release.
“Our goal is not to replace one rigid approach with another,” he continued. “It is to support rigorous, modern science—including animal studies when they remain appropriate and validated alternatives when they can provide the evidence needed to protect patients.”
The terminology change is the latest step in a regulatory transition already underway at the agency. The FDA launched its Roadmap to Reducing Animal Testing in Preclinical Safety Studies in April 2025, followed this March by draft guidance setting out how drug developers should validate NAMs for regulatory use. By April 2026, the agency said it had already reduced some unnecessary nonhuman primate testing and established pathways for qualifying alternative methods.
The regulatory update brings FDA terminology in line with the Food and Drug Omnibus Reform Act of 2022 (FDORA), which recognized both traditional animal studies and newer non-animal approaches as potential methods for generating evidence before human trials.
Alongside replacing “animal” with “nonclinical,” the FDA is updating related terminology, including “preclinical” and “in vitro,” and formally defining “nonclinical test” and “nonclinical study.”
The previous language could suggest a particular testing method rather than the evidence regulators require. The new terminology instead encompasses multiple approaches, allowing developers to select validated methods according to the scientific question being investigated. The FDA said the change imposes no new costs or requirements on developers and does not alter existing evidentiary standards.
Alongside the rule, the FDA has launched a database showing how NAMs are already being applied within drug development. Its initial release contains 25 examples drawn from publicly available FDA review materials.
The database is intended to demonstrate practical applications of emerging testing approaches and provide developers with examples of where the agency has encountered NAM-generated evidence.
The technologies encompassed by NAMs can include tests using human cells and tissues, computational models, and other approaches designed to generate safety information without relying exclusively on animals. The regulatory change is part of a wider push by the Department of Health and Human Services and the FDA to incorporate emerging technologies into drug development. The agency argues that some NAMs could more closely reflect human biology, although their use remains dependent on sufficient validation and suitability for the particular product and regulatory question.
For industries developing technologies that could eventually reduce reliance on animal testing, that qualification remains important: The FDA is not replacing animal studies wholesale with a new mandated testing system. It is formally creating room for alternative methods when the science supports their use.
The immediate rule applies to drugs and biological products intended for human use rather than creating new testing requirements for cosmetics. But the shift is relevant to the beauty industry because it further develops the regulatory and scientific infrastructure surrounding non-animal safety testing.
US law does not specifically require animal testing to substantiate the safety of cosmetics, with manufacturers instead responsible for ensuring their products are safe. The FDA has long supported the development and use of scientifically valid alternatives that can reduce or replace animal testing.
The new rule does not change those requirements for beauty companies. Its significance for the industry instead lies in the broader regulatory acceptance of non-animal testing methods. As NAMs gain greater use and validation within the more tightly regulated pharmaceutical sector, technologies could build a stronger body of evidence and regulatory precedent around their use.
Cosmetics are not subject to an FDA requirement for animal testing, and the new rule does not change how cosmetics companies must substantiate product safety. But many of the technologies being developed as NAMs have applications across regulatory categories. As those methods accumulate validation data and regulatory precedent in pharmaceuticals, the infrastructure surrounding non-animal safety assessment becomes considerably more mature.
For beauty companies, ingredient suppliers, testing laboratories, and technology developers working on alternatives, greater regulatory acceptance of NAMs in the more tightly regulated pharmaceutical sector could also help advance the validation and adoption of technologies with applications beyond drugs.
It’s worth noting, however, that the new rule is not necessarily final. The FDA is accepting public comments and has simultaneously published a companion proposed rule. If the agency receives significant adverse comment on the direct final rule, it will withdraw it and proceed through the conventional notice-and-comment rulemaking process.