FDA restates that tirzepatide is on neither the shortage list nor the 503B bulks list

The U.S. Food and Drug Administration issued an update on April 1, 2026 reminding pharmacies and outsourcing facilities of the conditions compounded drugs must meet to qualify for exemptions under sections 503A and 503B of the Federal Food, Drug, and Cosmetic Act. The agency stated plainly that tirzepatide and semaglutide "do not currently appear on the 503B bulks list or on FDA's drug shortage list" ^[1].

That combination matters because it closes both of the main doors that let outsourcing facilities legally compound copies of these drugs from bulk active ingredient. Under section 503B, FDA says outsourcing facilities are restricted from compounding with bulk drug substances unless the substance appears on the 503B bulks list — a list identifying substances for which there is a clinical need — or the drug compounded from that substance is on FDA's drug shortage list at the time of compounding, distribution and dispensing ^[1]. Neither applies to tirzepatide or semaglutide right now ^[1].

What the "essentially a copy" rules say

For state-licensed pharmacies and physicians compounding under section 503A, FDA restated two conditions: the product must be compounded for an individual patient based on receipt of a prescription, and the compounder must not compound, regularly or in inordinate amounts, drugs that are essentially copies of a commercially available drug product ^[1].

FDA said it intends to treat a compounded product as essentially a copy if it has the same active pharmaceutical ingredient as the commercially available product in the same, similar or an easily substitutable strength, and the commercial product can be used by the same route of administration prescribed for the compounded product — regardless of how the commercial product is labeled ^[1]. The exception is when a prescriber determines and documents that the compounded version contains a change producing a significant difference for an identified individual patient ^[1].

The agency applied the same logic to combination products. It offered a specific example: a compounded product that combines semaglutide API with another ingredient such as vitamin B12 (cyanocobalamin) may be considered essentially a copy when the products share the same route of administration — for instance, both injectable — and when the amounts of semaglutide and vitamin B12 in the compounded product are within 10% of the strengths of the respective commercially available products ^[1].

FDA also described a volume threshold. At this time, the agency said, it does not intend to take action against a compounder for compounding an essentially-a-copy product regularly or in inordinate amounts if the compounder fills four or fewer prescriptions of that compounded product during a calendar month ^[1].

Why it matters for patients

Compounded semaglutide and tirzepatide have been widely marketed at lower prices than Ozempic, Wegovy, Mounjaro and Zepbound. The legal basis for mass-market compounding largely rested on shortage status, and FDA's update confirms that basis is gone for both molecules ^[1].

The four-prescriptions-per-month figure is an enforcement posture, not a guaranteed safe harbor, and it is far below the volumes that large telehealth-linked compounding operations have handled. Patients who currently receive compounded versions of these drugs — including semaglutide combined with vitamin B12 — may see suppliers change what they offer, how they describe products, or what documentation they request from prescribers, since FDA specifically flagged the prescriber's determination of a significant difference as the route to an exception ^[1].

FDA also repeated a caution it has used before: even where it says it does not intend to act on shortage-related conditions, it may still take action for violations of other statutory or regulatory requirements, including findings that a product may be substandard or otherwise unsafe ^[1].

What this update does not say is also worth noting. The sources do not state how FDA will verify prescription counts, whether any enforcement cases are underway, or what the update means for oral compounded products or for other GLP-1 molecules such as orforglipron (Foundayo). Pricing effects are not addressed in the FDA document.

How the timeline got here

FDA determined the tirzepatide injection shortage resolved on December 19, 2024, and the semaglutide injection shortage resolved on February 21, 2025 ^[1]. Grace periods followed. After a district court denied the plaintiffs' preliminary injunction motion in Outsourcing Facilities Association v. FDA on March 5, 2025, enforcement discretion for 503A tirzepatide compounding ended, with 503B discretion running to March 19, 2025 ^[1]. A parallel ruling on April 24, 2025 ended 503A discretion for semaglutide, with 503B discretion running to May 22, 2025 ^[1].

What happens next

FDA said it "continues to actively monitor drug availability" ^[1]. Bulks list and shortage list status can change; the agency did not announce a scheduled review date for either molecule in this update.