FDA spells out what counts as "essentially a copy" for compounded GLP-1s

The U.S. Food and Drug Administration on April 1, 2026 issued a statement spelling out when a compounded GLP-1 product counts as "essentially a copy" of a commercially available drug — a line that federal law generally bars pharmacy compounders from crossing ^[1]. Attorneys at Foley & Lardner said it is the first time the agency has expressly stated what it considers to be compounding an essential copy "regularly or in inordinate amounts" ^[2].

What FDA said

Under Section 503A of the Federal Food, Drug, and Cosmetic Act, a state-licensed pharmacy or physician may compound a drug only for an identified individual patient based on receipt of a prescription, and may not regularly or in inordinate amounts compound products that are essentially copies of commercially available drugs ^[1].

FDA said it intends to treat a compounded product as essentially a copy if two things are true: the compounded product has the same active pharmaceutical ingredient (API) as the commercially available drug in the same, similar, or an easily substitutable strength; and the commercially available drug can be used by the same route of administration prescribed for the compounded product, regardless of how the commercial product is labeled ^[1][2].

There is one exception. The product is not treated as a copy if a prescriber determines and documents that the compounded version contains a change that produces a significant difference from the commercial drug for that identified individual patient ^[1]. Foley notes FDA has not said what kind or amount of documentation a prescriber must create and keep to support that determination ^[2].

The semaglutide plus B12 example

FDA applied the same logic to combination products — those containing the same APIs as two or more commercially available drugs ^[1]. As an illustration, the agency said it may consider a compounded product that combines semaglutide API with another API such as vitamin B12 (cyanocobalamin) to be essentially a copy when the compounded product is given the same way as the commercially available products, such as by injection, and when the amounts of semaglutide and vitamin B12 are within 10% of the strengths of the respective commercially available products ^[1][2].

That matters because semaglutide-plus-B12 blends have been a common format in the compounded market. FDA's 10% figure gives a concrete yardstick that did not previously exist in public agency statements.

The four-prescription threshold

FDA also said that, at this time, it does not intend to take action against a compounder for compounding an essential copy "regularly or in inordinate amounts" if the compounder fills four or fewer prescriptions of that compounded product during a calendar month ^[1][2]. That is an enforcement-discretion statement, not a legal safe harbor. Foley points out the statement is a clarification of FDA policy and "does not have the force and effect of law" ^[2].

Separately, FDA reminded 503B outsourcing facilities that they may not compound from bulk drug substances unless the substance is on the 503B bulks list or the compounded drug is on FDA's drug shortage list at the time of compounding, distribution and dispensing ^[1]. The agency stated plainly that tirzepatide and semaglutide do not currently appear on the 503B bulks list or on FDA's shortage list ^[1][2].

Why it matters for patients

The practical effect is narrower supply of large-scale compounded semaglutide and tirzepatide, including the B12 combinations that some telehealth sellers have marketed as different from the brand products. Under FDA's stated approach, adding B12 at a similar strength and the same injectable route does not by itself make a product something other than a copy ^[1][2].

The four-or-fewer-prescriptions-per-month figure is a compounder-level threshold, not a patient allowance. It suggests FDA is focused on high-volume operations rather than one-off personalized preparations, but it does not guarantee that any individual patient's compounded prescription will continue to be filled.

The prescriber-documented "significant difference" pathway remains open, and it is the main route by which a compounded GLP-1 could still be dispensed for a specific patient ^[1]. Because FDA has not described the documentation standard, how strictly that pathway is applied is not yet known ^[2].

It is also worth remembering that compounded drugs are not FDA approved, meaning the agency does not review their safety, effectiveness or quality before marketing; products that are unlawful copies may be considered misbranded, exposing compounders to warning letters, seizure or injunction ^[2].

Background and what happens next

FDA declared the tirzepatide shortage resolved on December 19, 2024 and the semaglutide injection shortage resolved on February 21, 2025 ^[1]. After a federal court in Texas denied preliminary injunction motions in Outsourcing Facilities Association v. FDA on March 5 and April 24, 2025, the 503A enforcement-discretion periods ended, with 503B discretion running to March 19 and May 22, 2025 respectively ^[1].

FDA framed the April 2026 statement as coming "as national GLP-1 supply begins to stabilize" ^[1]. The agency did not announce a comment period, effective date or future rulemaking in the statement, so no further dated milestones are known from these sources.