The 503B bulks list proposal publishes in the Federal Register

The Food and Drug Administration published a notice in the Federal Register on May 1, 2026 laying out which bulk drug substances it proposes to place on — and leave off — the list of substances outsourcing facilities may use under section 503B of the Federal Food, Drug, and Cosmetic Act. Semaglutide, tirzepatide and liraglutide all appear in the section titled "Substances Evaluated and Not Proposed for Inclusion on the 503B Bulks List" ^[1].

The notice carries the citation 91 FR 23431, document number 2026-08552, and runs 14 pages, from page 23431 to 23444. It was filed under Docket No. FDA-2018-N-3240, the long-running docket FDA has used for this list since at least 2020 ^[1]. The published dates text states that "Either electronic or written comments on the notice must be submitted by June 30, 2026" ^[1].

What the notice covers

The document's table of contents shows FDA worked through each of the three GLP-1 substances separately, using the same framework for each: whether an FDA-approved drug product is suitable, and whether the proposed compounded product must be made from a bulk drug substance at all, followed by a response to comments already filed on the docket ^[1].

For semaglutide, the notice includes subsections on "oral sublingual" and buccal products, injectable products, oral products, "proposals for formulations without certain excipients," and multi-ingredient products ^[1]. Those headings track the kinds of compounded versions that have been sold in the US market — sublingual drops, injectables in different concentrations, combination products, and versions marketed as leaving out particular inactive ingredients.

The tirzepatide section is structured almost identically, with subsections on oral, "oral sublingual" and buccal products, injectable products, and multi-ingredient products ^[1]. The liraglutide section is shorter, covering only the suitability of approved products, the bulk-substance question and docket comments ^[1].

The source material available here is the Federal Register's document record and its list of section headings. The agency's full reasoning for each substance, and any conditions or exceptions it may have described in the text, are not reproduced in what is available, so the specific findings behind each heading are not yet known from this source.

Why it matters for patients

Section 503B outsourcing facilities are the larger compounders that can make drugs in batches without patient-specific prescriptions. Under the statute named in this notice, the bulk drug substances they may use are limited to those FDA determines there is a clinical need for ^[1]. A proposal not to include semaglutide, tirzepatide and liraglutide would, if finalized, bear directly on whether those facilities can legally use bulk GLP-1 powder to make compounded copies.

This is a proposal open for comment, not a final list. Nothing in the May 1 notice is described as an immediate ban, and the document is classified as a "Notice," not a rule ^[1]. Anyone taking a compounded GLP-1 product may want to follow the docket, because the outcome could affect what remains available from outsourcing facilities. The notice also signals that FDA looked specifically at sublingual, buccal, oral, injectable, multi-ingredient and excipient-free formulations — the marketing claims used to argue that a compounded version differs from the approved drug ^[1].

What this notice does not address, based on the record available, is compounding under section 503A by traditional pharmacies, which is governed separately.

What happens next

• May 1, 2026: the notice publishes at 91 FR 23431 and the comment period opens ^[1].
• June 26, 2026: FDA publishes a follow-up notice in the same docket, document 2026-12937, with the action "Notice; extension of comment period" ^[1]. The new closing date is not stated in the record available here.
• June 30, 2026: the original comment deadline stated in the May 1 notice ^[1].

After comments close, FDA would normally review submissions before issuing a final determination. No date for a final list has been announced in this source.