FDA Moves to Permanently Close the 503B Compounding Pathway for GLP-1 Drugs

On April 30, 2026, the FDA proposed formally excluding semaglutide, tirzepatide, and liraglutide from the 503B bulks list — the list of bulk drug substances that outsourcing facilities are permitted to compound from under federal law. This goes a step further than simply letting the shortage-based exemption lapse, which we covered when the underlying shortages were resolved.

Outsourcing facilities can generally compound from a bulk substance in two circumstances: when that substance is on the 503B bulks list, or when the finished drug is on the FDA's shortage list. Once semaglutide and tirzepatide came off the shortage list, compounding under that second pathway ended — but a substance could still in theory be added to the 503B bulks list on its own merits. This proposal would foreclose that too, by formally finding no clinical need for outsourcing-facility compounding of these three drugs absent a shortage.

The FDA's proposal cites more than 455 adverse event reports linked to compounded semaglutide and more than 320 linked to compounded tirzepatide, with many involving dosing errors tied to patients self-administering from multidose vials — a different, and by the agency's account riskier, format than the fixed-dose pens used for the FDA-approved products.

The public comment period on the proposal closed June 29, 2026. As of this writing, the FDA has not published a final rule. A proposed rule is not enforceable on its own — check the FDA's press announcement page directly for whether and when this has been finalized before assuming the compounding pathway is fully closed.