FDA Has Proposed Keeping Semaglutide and Tirzepatide Off the 503B Bulks List

On 1 May 2026 the FDA proposed not to include semaglutide, tirzepatide or liraglutide on the 503B Bulks List — the list of active ingredients outsourcing facilities may lawfully compound from. The comment period, extended once, closed on 30 July 2026. A final decision was still pending as of 4 September 2026.

This is the quieter of the two mechanisms that govern compounded GLP-1s, and it is the one that matters from here.

What the 503B Bulks List actually is

Section 503B of the Federal Food, Drug, and Cosmetic Act created a category of compounder called an outsourcing facility — a registered operation that may compound in larger batches, without an individual prescription for each unit, and is held to stricter manufacturing standards than a traditional pharmacy.

Outsourcing facilities may compound from a bulk active ingredient in two situations. Either the ingredient appears on the FDA's drug shortage list, or it appears on the 503B Bulks List — the list of substances for which the agency has determined there is a clinical need. See the Federal Register notice of 1 May 2026.

Those two doors are the whole story. Shortage-based compounding is temporary by design: it ends when the shortage does. The Bulks List is the durable one.

What the FDA proposed for the 503B Bulks List

In a notice published on 1 May 2026 (91 FR 23431), the FDA requested comment on its proposal not to include semaglutide, tirzepatide or liraglutide on the list.

On 26 June the agency extended the comment period in response to a request for more time, setting a new deadline of 30 July 2026.

The wording matters. This is a proposal about clinical need — the statutory test — not a safety finding about the molecules, all three of which are FDA-approved as finished products. The question put out for comment is whether outsourcing facilities have a clinical reason to compound from the bulk ingredient when approved finished products exist.

Why this is the consequential door

Compounded GLP-1s reached a very large number of people through the shortage route. That route is inherently temporary, and the whole compounded-GLP-1 market has operated in the knowledge that it closes when supply normalises.

A durable compounding market would need the Bulks List. If the FDA finalises the proposal as published, that second door does not open for these three substances — which leaves compounded semaglutide and tirzepatide without a general lawful basis at outsourcing-facility scale.

Traditional 503A pharmacy compounding operates under different provisions and is not directly governed by this list. It is also a different scale of operation, and it faces its own constraints where an approved product exists. The FDA's compounding laws and policies page sets out both.

What this does not say

Three things this notice is routinely misread as saying, and does not:

• It is not a statement that these drugs are unsafe. All three are FDA-approved finished products. The proposal is about a compounding authorisation, not an approval.
• It is not a ban on the medicines. Prescriptions for the approved products are unaffected.
• It is not final. As of the date on this article the comment period has closed and the agency has not published a final determination.

What to watch next on the 503B Bulks List

The next document in this sequence is the FDA's response to comments and its final decision. It will appear in the Federal Register, and we will report it here with the date attached.

Anyone currently using a compounded GLP-1 has a practical question rather than a regulatory one — what happens to their supply — and that is a conversation with the prescriber, not something a regulatory notice answers.

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• The FDA status tracker — current status for every compound we cover