FDA Proposal Would Leave Semaglutide, Tirzepatide, and Liraglutide Off 503B Bulks List

On April 30, 2026, the U.S. Food and Drug Administration (FDA) announced a proposal to exclude semaglutide, tirzepatide, and liraglutide from the 503B Bulk Drug Substances List (“503B Bulks List”)—finding no clinical need for outsourcing facilities to compound the three drugs from bulk substances absent a drug shortage.

“When FDA-approved drugs are available, outsourcing facilities cannot lawfully compound using bulk drug substances unless there is a clear clinical need,” FDA Commissioner Marty Makary said in the agency’s announcement. “This action reflects our responsibility to protect patients and preserve the integrity of the drug approval process while continuing to provide a transparent, science-based pathway for public input.”

If the FDA moves forward with its proposal, this would be a victory for drug manufacturers, and loss for drug compounders, in the drug compounding debate over GLP-1 drugs sold for weight loss and type 2 diabetes. Semaglutide is FDA-approved under the brand-names Wegovy (weight loss), Ozempic (type 2 diabetes, cardiovascular risk reduction), and Rybelsus (type 2 diabetes). Tirzepatide is FDA-approved as Mounjaro (type 2 diabetes) and Zepbound (weight loss). Liraglutide is FDA-approved under the brand-names Saxenda (weight loss) and Victoza (type 2 diabetes, cardiovascular risk reduction).

503B Bulks List

The 503B Bulks List identifies bulk drug substances that outsourcing facilities may use in drug compounding. Generally, outsourcing facilities—which are subject to the conditions of section 503B of the federal Food, Drug, and Cosmetic Act (FD&C Act)—may not compound a drug product that includes a bulk drug substance unless:

1) the substance appears on the 503B Bulks List, identifying bulk drug substances for which there is a clinical need; or

2) the drug product compounded from such bulk drug substance is on the FDA’s drug shortage list at the time of compounding, distribution, and dispensing. When appearing on the drug shortages list, a drug may be compounded if the compounders meet certain federal law conditions and requirements.

Semaglutide products were added to the drug shortage list in 2022 and removed in 2025. Tirzepatide was added in 2022 and removed in 2024. Removing the substances from the 503B Bulks List, therefore, removes the remaining pathway. Liraglutide injection remains on the shortage list currently, and therefore can be compounded by 503Bs at this time despite its absence from the 503B Bulks List.

‘No Basis to Conclude’

The May 1, 2026, Federal Register Notice, “List of Bulk Drug Substances for Which There Is a Clinical Need Under Section 503B of the Federal Food, Drug, and Cosmetic Act,” 91 Fed. Reg. 23431, describes the background and methodology for developing the 503B Bulks List, as well as the reasons for the exclusion of the three substances.

“FDA has not identified a basis to conclude that the oral and injectable routes of administration of the FDA-approved semaglutide products cause those products to be medically unsuitable for certain patients and that a compounded buccal or sublingual product would address such an attribute,” the FDA states at 23435 (tirzepatide at 23440). Similarly, the agency states that it “tentatively finds no basis to conclude that there is an attribute of the FDA-approved drug products containing liraglutide that makes them medically unsuitable to treat certain patients for a condition that FDA has identified for evaluation and that the proposed compounded products are intended to address.” (23443).

503A Compounding is Not Impacted by the FDA Decision, But Faces Uncertainties

The FDA’s decision not to include these GLP-1s on the bulk compounding list does not affect their use by 503A pharmacies which are permitted, subject to various requirements, to compound with active ingredients found in FDA-approved drug products. However, FDA has taken measures to constrain certain activities of 503A compounders by, for example, sending warning letters to pharmacies and telemedicine practices which it believes suggest equivalence of compounded an approved medications, and clarifying conditions under which it will consider 503A-compounded medications to be “essentially a copy” of approved medications (and thus non-compoundable, except in instances of drug shortage), including certain drug combinations (e.g., combinations of GLP-1s with Vitamin B12, falling outside of certain parameters).

At the same time, FDA is currently considering addition of certain peptide active ingredients that are not found in FDA approved drugs to the list of bulk ingredients—this will be a topic of a July 2026 FDA Advisory Committee meeting. Among the peptides to be considered are MOTs-C for uses related to treatment of obesity, and other peptides for a variety of other conditions.

Takeaways

Stakeholders with an interest in the outcome should submit comments electronically to www.regulations.gov (or by mail at the Federal Register notice, 91 Fed. Reg. 23431 (May 1, 2026)) through June 30, 2026. Late comments will not be considered. The Federal Register notice states that additional bulk drug substances nominated for inclusion on this list are under consideration and may be the subject of future notices. If you have questions, please reach out to the authors.

Epstein Becker Green Staff Attorney Ann W. Parks contributed to the preparation of this post.