The U.S. Food and Drug Administration (FDA) has issued a direct final rule updating nonclinical testing terminology across its drug and biological product regulations.
According to the Federal Register notice, the rule replaces phrases such as “animal tests” and “animal studies” with “nonclinical tests” and “nonclinical studies.” The regulatory change aligns with the Food and Drug Omnibus Reform Act of 2022, which formally recognized that alternative methods — such as in vitro systems and computational models — can generate safety evidence for human clinical trials alongside traditional animal studies.
While the FDA noted that the rule does not eliminate, prohibit, or change the evidentiary standards for animal studies, it removes language suggesting that animal testing is the only acceptable pathway for generating safety data for regulatory decisions.
For the preclinical and contract research sectors, this regulatory shift formalizes the agency’s growing support for new approach methodologies (NAMs). Addressing the change, the FDA stated its goal 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 FDA is accepting public comments on the rule. If no significant adverse comments are received by December 7, 2026, the rule will take effect in February 2027.