The question whether an administrative agency has unfairly “changed the rules” is central in many challenges to regulations. On April 2, the Supreme Court addressed a particularly hard-fought dispute about that issue in FDA v. Wages & White Lion Investments, LLC, a case about the FDA’s denial of marketing authorization for flavored e-cigarette products.

The en banc Fifth Circuit held that the FDA acted arbitrarily and capriciously by applying different standards than those stated in its predecisional guidance documents, and by failing to review marketing plans previously deemed critical.

The Supreme Court held that the FDA’s denial orders were consistent with its predecisional guidance about scientific evidence, comparative efficacy, and device type. The Court concluded that the FDA’s guidance documents did not commit to any specific type of study, and that the FDA’s requirement for manufacturers to compare their flavored products to tobacco-flavored products was a natural consequence of its guidance. No. 23-1038 (U.S. Apr. 2, 2025).