The FDA’s May 1, 2026 proposal to formally exclude semaglutide, tirzepatide, and liraglutide from the 503B outsourcing facility bulks list remains unfinalized as of October 11, 2026. A Federal Register search confirmed that no final notice has been published.
The comment period closed on July 30, 2026, following a 30-day extension. More than two months later, the agency has not issued a final rule, leaving the proposed exclusion without legal effect.
For 503B outsourcing facilities and compounding pharmacies that rely on these GLP-1 ingredients for office-stock formulations, the extended timeline signals continued regulatory uncertainty — but also means the 503B pathway for these bulk substances remains open for now.
What happened
On May 1, 2026, the FDA proposed removing semaglutide, tirzepatide, and liraglutide from the 503B bulks list, which identifies bulk drug substances that outsourcing facilities may use to compound drugs.
The original comment period was extended by 30 days, ultimately closing on July 30, 2026. As of October 11, 2026, a search of the Federal Register confirmed that no final notice has been published. The proposal therefore remains in its proposed stage and carries no legal force.
In its proposal, the FDA addressed arguments from nominators who sought to keep these substances on the bulks list by pointing to dose differentiation as a rationale. The agency cited a 245-person Phase 2 clinical trial in which 16 mg weekly semaglutide did not significantly lower HbA1c more than 2 mg in its primary analysis, addressing the claim that compounded higher-dose formulations fill a clinical gap.
Why it matters
Until a final rule is published, the 503B exclusion remains a proposal with no legal effect. Outsourcing facilities may continue to use these bulk substances for now, under the regulatory frameworks currently in place.
However, the extended timeline creates ongoing uncertainty for large-scale compounders, telehealth GLP-1 platforms, pharmacy benefit managers, and patients who depend on compounded GLP-1 products. If finalized, the rule would permanently close the 503B compounding pathway for these three ingredients — even during future drug shortages.
What to watch next
- Watch the Federal Register for any final notice or supplementary proposal from the FDA.
- Monitor whether the agency issues additional guidance or enforcement updates related to 503B GLP-1 compounding in the interim.
- Track any legal challenges or stakeholder petitions that may arise if the exclusion is finalized.
- Follow how outsourcing facilities adjust their office-stock formulations and product offerings in response to the ongoing uncertainty.
Sources
Industry information only. Not medical or legal advice.
