Peptides
FDA has proposed to keep semaglutide and tirzepatide off the 503B list
The FDA has proposed not to include semaglutide, tirzepatide or liraglutide on the 503B Bulks List — the list of bulk drug substances outsourcing facilities may use in compounding. The proposal appeared on 1 May 2026 (91 FR 23431, Docket FDA-2018-N-3240). The comment period was extended and closed on 30 July 2026. No final determination has been made.
Section 503B of the Federal Food, Drug, and Cosmetic Act lets a registered outsourcing facility compound from a bulk drug substance only where the FDA has identified a clinical need for it. That identification is the 503B Bulks List. A substance that is not on the list, and is not otherwise eligible, is not available to an outsourcing facility as a bulk starting material.
On 1 May 2026 the agency published a notice requesting comment on its proposal not to include three GLP-1 substances — semaglutide, tirzepatide and liraglutide — on that list. On 26 June 2026 it extended the comment period in response to a request for more time, and that extended period closed at 11:59 p.m. Eastern on 30 July 2026. The FDA states that the comments will inform its final determination whether to include these substances.
For a practice whose GLP-1 program is supplied by an outsourcing facility compounding from bulk, the question this decides is whether that supply route remains open at all. It is a separate question from section 503A, which governs compounding against a prescription for an identified patient, and separate again from whether a drug is on the shortage list.
What changed
The FDA has put its proposal on the record and taken comment on it, and the comment window has now closed.
What did not change
Nothing is decided. This is a proposal with a closed comment period, not a determination, and the 503B Bulks List is unchanged until the FDA makes one.
Who this reaches
Any practice or platform whose GLP-1 supply depends on an outsourcing facility compounding from bulk semaglutide, tirzepatide or liraglutide. The time to submit comment has passed; what remains is knowing which of your supply arrangements depend on the outcome, and what the alternative is if the FDA finalizes as proposed.
Common questions
Does this mean compounded semaglutide is banned?
No. It is a proposal about one route — whether outsourcing facilities may use these substances as bulk starting material under section 503B. The FDA has not made a final determination, and the proposal does not address section 503A compounding against a prescription for an identified patient, which is governed separately.
Can we still submit a comment?
No. The comment period opened on 1 May 2026, was extended on 26 June, and closed at 11:59 p.m. Eastern on 30 July 2026 under Docket FDA-2018-N-3240. The FDA states that late filed comments will not be considered.
What should a clinic do while this is pending?
Establish which of its supply agreements actually rely on 503B bulk compounding of these substances rather than on another route, and what the agreement says happens if the route closes. That is a question about the contract and the pharmacy relationship, and it is cheaper to answer now than during a supply interruption.
Does this reach your business?
Every matter turns on its facts. Mr. Sheehan reviews each inquiry himself.