Final rule · 2026-19350

Nonclinical Testing Terminology

The Food and Drug Administration (FDA, Agency, or we) is issuing a direct final rule that substitutes references to "animal" tests or studies with "nonclinical" tests or studies, adds a definition of the terms "nonclinical test" and "nonclinical study," and makes other comparable or conforming amendments in certain safety and reporting sections of its regulations. The direct final rule also substitutes "nonclinical" for "preclinical" and "in vitro" for consistency in terminology. The Agency is issuing these amendments directly as a final rule because we believe they are noncontroversial changes in terminology that are not expected to affect industry practice and FDA anticipates no significant adverse comments. These amendments align with recent amendments to the Federal Food, Drug, and Cosmetic Act (FD&C Act) and the Public Health Service Act (PHS Act) and are intended to remove an emphasis, in certain places, on the use of animal testing as the only scientific methodology to assess the safety of a drug in the nonclinical setting. These changes may also foster the development and use of scientifically valid new testing methodologies, potentially improving predictive accuracy of product safety testing while replacing, reducing, or refining animal use. The rule adds no new requirements.