FDA Challenges Use of 'Same Active Ingredient' in Compounded Drug Advertising

In early February 2026, the U.S. Food and Drug Administration announced that it was taking issue with the use of the phrase “same active ingredient” in advertising for compounded drugs. FDA explained that it is concerned that claiming a compounded drug has the “same active ingredient” as an FDA-approved product is confusing to consumers.

FDA has a long regulatory history around establishing “active ingredient” sameness, which predates the issue becoming relevant for compounding. In the context of generic drug development, the agency has long required that a generic drug’s active ingredient be identical to that of the reference listed drug, a requirement codified in 21 CFR 314.3(b) and 314.92(a)(1) and explained in draft guidance on “Sameness Evaluations in an ANDA — Active Ingredients.” According to that guidance, FDA intentionally takes a flexible approach in determining active ingredient sameness, and an active ingredient does not have to be obtained from the brand manufacturer to be the “same” as that in a reference listed drug.

The 1992 preamble to the final rule implementing the Hatch-Waxman amendments stated that an active ingredient is the same if it meets the same standards of identity, which in most cases are described in the United States Pharmacopoeia. If there is no USP standard, FDA may prescribe additional standards to establish the identity of the molecule. FDA’s framework for establishing active ingredient sameness provides that it is established using well-understood scientific methods, as limiting “sameness” to ingredients obtained from brand manufacturers would stifle generic competition.

When the Drug Quality and Security Act was passed in 2013, Sections 503A and 503B of the Federal Food, Drug, and Cosmetic Act took a similar approach. According to the statute, drugs must be compounded using an active ingredient that complies with a USP monograph or, if a monograph does not exist, is a component of a drug approved by FDA. The process for identifying the active pharmaceutical ingredient that may be used in a compounded drug echoes that for generics.

FDA guidance documents and public statements have, for years, used the phrase “same active ingredient” or “same API” to describe the relationship between compounded drugs and their FDA-approved counterparts, particularly when discussing the legal requirements for compounding under Section 503A. The new enforcement approach creates uncertainty for how companies engaged in the development, marketing and sale of compounded and generic drugs communicate with patients, health-care professionals and customers.