Compounding pharmacies filling semaglutide and tirzepatide prescriptions are back inside a restriction that shortage status had suspended for more than two years. The Food and Drug Administration determined the tirzepatide shortage resolved in December 2024 and the semaglutide shortage resolved in February 2025. Once each enforcement discretion period ran out, the Federal Food, Drug, and Cosmetic Act's bar on compounding drugs that are essentially copies of a commercially available drug product applied again to GLP-1 formulations, and every pharmacy still compounding them needs a defensible essentially-a-copy analysis behind each prescription.
The Essentially-a-Copy Test Under Section 503A
Section 503A(b)(1)(D) of the FDCA, codified at 21 U.S.C. § 353a(b)(1)(D), denies the compounding exemptions from FDA approval, adequate-directions labeling, and current good manufacturing practice to a pharmacist or physician who compounds regularly or in inordinate amounts any drug that is essentially a copy of a commercially available drug product. FDA's January 2018 guidance sets out a three-part test: the compounded drug has the same active pharmaceutical ingredient as the commercial product, a dosage strength that is the same, similar, or easily substitutable (FDA treats strengths within 10 percent of each other as similar), and the same route of administration, or one the commercial product could also be used for. A drug that shares all three characteristics is essentially a copy, and the same analysis applies to a compound that combines two or more commercially available drugs in comparable strengths.
The Change-for-a-Particular-Patient Exception
The statute excludes from essentially-a-copy status any drug in which a prescriber makes a change, for an identified individual patient, that produces a significant difference for that patient compared to the commercially available drug. FDA's guidance treats the prescription itself as the record of that determination. A notation naming the change and the reason, such as removing a dye because of a documented allergy, converting a tablet to a liquid for a patient who cannot swallow pills, or raising a dose above what the commercial product offers, satisfies the exception. A patient's name paired with a drug formulation, without more, does not, and neither does a lower price; Congress specifically excluded cost from the factors a compounder can rely on. Outsourcing facilities compounding under Section 503B follow a parallel clinical-difference standard and remain subject to current good manufacturing practice requirements that 503A compounders are exempt from, so a pharmacy weighing whether to register as an outsourcing facility needs both analyses done correctly.
The change-for-a-patient exception lives or dies on the prescription note. A determination that exists only in a pharmacist's memory does not satisfy Section 503A when FDA or a state board asks for the record.
Documentation and the Regularly-or-Inordinate-Amounts Standard
A properly documented significant-difference exception does not eliminate the second half of the statute. FDA still looks at how often a pharmacy fills the same essentially-a-copy drug. The agency's policy is not to pursue action against a compounder that fills four or fewer prescriptions for the same compounded drug in a calendar month, counting each refill as a separate prescription. Beyond that volume, or where a pharmacy keeps pre-printed prescription pads for the compound, routinely substitutes it for the commercial product, or fills it on a standing schedule rather than as prescriptions arrive, FDA treats the pattern as regular or inordinate compounding. FDA recommends retaining prescription notations and volume records for at least three years, the same records a state board of pharmacy inspection will ask to see.
Why Early Legal Counsel Is Critical
A compounding pharmacy that receives an FDA Form 483 observation, a warning letter, or a state board of pharmacy inquiry citing essentially-a-copy compounding benefits from involving counsel before responding. Reconstructing significant-difference documentation after an inspection has already begun is a materially weaker position than documenting it at the time each prescription was filled, and correspondence sent to FDA or a state board without understanding how the three-part test and the regularly-or-inordinate-amounts standard apply to the pharmacy's specific volume can concede points that are difficult to recover. Early counsel can help a pharmacy audit its own prescription files against the standard before an inspector does.
How Health Law Alliance Can Help
Health Law Alliance represents compounding pharmacies in FDA warning letter responses, state board of pharmacy inspections, and DEA registration matters connected to essentially-a-copy compounding, semaglutide and tirzepatide dispensing, and the broader 503A and 503B regulatory framework, as part of the firm's compounding pharmacy defense practice. If your pharmacy needs its prescription documentation reviewed against FDA's essentially-a-copy standard, contact us for a free, confidential consultation.
