FDA sets a four-prescriptions-a-month yardstick for copy compounding

The FDA on April 1, 2026, restated the rules that limit compounded GLP-1 drugs and added a specific number: the agency said it does not intend to take action against a compounder for making a drug product that is "essentially a copy" of a commercially available drug "regularly or in inordinate amounts" if that compounder fills four or fewer prescriptions of that product in a calendar month ^[1]. The notice also confirmed that tirzepatide and semaglutide do not currently appear on the FDA's drug shortage list or on the 503B bulks list ^[1].

What the notice says

The statement is framed as a reminder about the conditions compounded drugs must meet to qualify for exemptions under sections 503A and 503B of the Federal Food, Drug, and Cosmetic Act ^[1]. Under 503A, which covers state-licensed pharmacies and physicians, the drug has to be compounded for an individual patient based on receipt of a prescription, and the compounder cannot make essentially copies of a commercially available drug product regularly or in inordinate amounts ^[1].

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

The agency applied the same logic to combination products. A compounded drug can be treated as essentially a copy if it contains the same active ingredients as two or more commercially available products at the same, similar, or easily substitutable strengths, by the same route ^[1]. The FDA's own example is a compound that combines semaglutide with another ingredient such as vitamin B12 (cyanocobalamin). That could be considered essentially a copy when both are injectables given the same way, and when the amounts of semaglutide and vitamin B12 in the compound fall within 10% of the strengths of the respective commercially available products ^[1].

For outsourcing facilities under 503B, the restriction is different. Those facilities cannot compound from bulk drug substances unless the substance appears on the 503B bulks list, which identifies substances with a clinical need, or the drug compounded from it is on the FDA drug shortage list at the time of compounding, distribution, and dispensing ^[1]. Neither semaglutide nor tirzepatide meets either condition right now ^[1].

Why it matters for patients

This is the clearest number the FDA has put on a rule that has been described in words since the GLP-1 shortages ended. The agency declared the tirzepatide injection shortage resolved on December 19, 2024, and the semaglutide injection shortage resolved on February 21, 2025, and the enforcement discretion windows that followed those decisions have since closed ^[1]. Federal courts declined to block the FDA in both of the Outsourcing Facilities Association cases, on March 5, 2025, for tirzepatide and April 24, 2025, for semaglutide ^[1].

For anyone still getting compounded semaglutide or tirzepatide, the four-prescriptions-a-month figure describes what the FDA says it will tolerate from a single pharmacy for a single copy product, not a per-patient allowance and not a green light for large-scale compounding ^[1]. It also does not change any other legal requirement. The FDA repeated across earlier updates that it may still act on violations of other statutory or regulatory requirements, including findings that a product may be substandard or otherwise unsafe ^[1].

The B12 example matters for a common marketing practice. Adding a second ingredient to a GLP-1 compound does not automatically move it outside the copy rules; under the stated approach, matching strengths within 10% of the commercial products by the same route can still make it essentially a copy unless a prescriber documents a significant difference for that individual patient ^[1].

What happens next

The notice sets no new deadline or expiration date, and the FDA did not say whether it plans to revisit the four-prescription figure ^[1]. Whether semaglutide or tirzepatide could return to the shortage list or be added to the 503B bulks list is not addressed in this statement; the agency said only that they do not currently appear on either ^[1]. The FDA has said in past updates that it continues to actively monitor drug availability ^[1].