FDA opens public comment on excluding semaglutide and tirzepatide from 503B bulks list

The FDA's May 4, 2026 proposed rule formally moves to exclude semaglutide and tirzepatide from the section 503B bulks list. If finalized, 503B outsourcing facilities — which produce most of the compounded GLP-1 supply that has scaled DTC peptide telehealth — would no longer be able to use these molecules as starting materials for compounding.

What stays legal under 503A

503A patient-specific compounding under documented medical necessity is unaffected by this proposal. The narrow exception preserves access for patients with documented hypersensitivity to a Wegovy or Zepbound excipient — a defensible but rare clinical pathway.

Public comment window

The rule enters a 90-day public comment window closing August 3, 2026. Final-rule publication and effective date typically run 6-18 months after comment close, depending on volume and complexity. Patients currently on compounded GLP-1s have at least the comment window plus the post-final-rule transition before mandatory supply changes take effect.

Affected supply

Industry estimates from Endpoints News and STAT put the compounded-GLP-1 patient population at 1.5-2.5 million as of early 2026. Most are served through 503B-supplied telehealth platforms (Hims & Hers, Mochi, Henry Meds). 503A compounding under medical necessity has lower throughput and is unlikely to absorb the full population at current volumes.