The compounded versions of semaglutide and tirzepatide that filled telehealth ads in recent years were legal for one narrow reason: federal law lets pharmacies copy a drug while it sits on the FDA's official shortage list. They were never approved stand-ins for Ozempic, Wegovy, Mounjaro, or Zepbound, and no agency ever reviewed them for safety or effectiveness. Once the FDA declared the shortages resolved (tirzepatide at the end of 2024, semaglutide in February 2025), the permission that had made those copies lawful expired on fixed deadlines, and compounding them as brand-name copies had to end. This piece takes you through how that switch worked.
Key points#
- Compounded GLP-1 drugs were permitted only because the brand-name products were listed as in shortage, not because anyone judged the copies safe or effective.
- A shortage listing temporarily switches off the legal rule against copying an approved drug. Removing the listing switches it back on.
- The FDA set staggered wind-down dates by pharmacy type, ending in the spring of 2025.
- "Approved," "compounded," and "research-only" are three different legal states, and a product can shift categories without ever becoming an approved medicine.
Start with the rule, not the exception#
To see why the copies appeared and then vanished, it helps if you read the law in the order the law actually runs.
The baseline rule is restrictive. Two sections of the Federal Food, Drug, and Cosmetic Act govern pharmacy compounding. Section 503A covers traditional compounding, where a licensed pharmacy prepares a medication tailored to an individual patient. Section 503B covers outsourcing facilities that make larger batches under tighter manufacturing standards. Both sections generally forbid compounding anything that is "essentially a copy" of a commercially available, FDA-approved product. In ordinary times, a pharmacy simply may not mass-produce its own semaglutide alongside the approved pens.
The exception is what changed. When a drug is on the FDA shortage list, that copy prohibition is relaxed so that patients are not left without a needed medicine. Demand for GLP-1 drugs had outrun the manufacturers' capacity to fill vials and pens, the approved products landed on the shortage list, and the "essentially a copy" bar came down. That single administrative fact, not any judgment about the compounded product itself, is what opened the market.
Read this way, the availability of compounded GLP-1 drugs was never a signal of quality. It was a downstream side effect of a supply gap in the approved products.
The switch flips back#
A shortage listing is not permanent. The FDA keeps reassessing supply, and when it concludes a manufacturer can meet national demand, it takes the drug off the list. The moment it does, the exception disappears and the ordinary copy prohibition applies again. Nothing about the molecule changes. Its regulatory status does.
That is exactly what happened here. For tirzepatide, the FDA found the shortage resolved and, after a court-ordered second look, reaffirmed that finding on December 19, 2024. For semaglutide, a decision memorandum dated February 21, 2025 concluded the injectable shortage was over. The agency issued formal declaratory orders documenting each determination.
Rather than force every pharmacy to halt on the same day, the FDA announced periods of enforcement discretion: defined windows during which it did not intend to act against compounders still finishing the wind-down. The deadlines were staggered by facility type:
- Tirzepatide: 503A pharmacies had until February 18, 2025; 503B outsourcing facilities until March 19, 2025.
- Semaglutide: 503A pharmacies had until April 22, 2025; 503B facilities until May 22, 2025.
After those dates, compounding these drugs as copies of the brand-name products no longer fell inside the shortage exception. The legality had always been tied to a list, not to the chemistry.
Why the FDA framed the copies as a safety question#
The agency did not treat the wind-down as a paperwork detail. Its reasoning rests on a structural gap: an approved drug has cleared FDA review for safety, effectiveness, and manufacturing quality, and a compounded product has not.
In its safety communication on unapproved GLP-1 drugs used for weight loss, the FDA described problems it says it actually observed, not hypothetical worries. It cited adverse-event reports involving dosing errors, including patients who drew the wrong amount from multi-dose vials and, in some cases, took many times the intended dose. It flagged inconsistency in the active ingredient, such as the use of different salt forms (semaglutide sodium or semaglutide acetate) rather than the base molecule studied in the approved products. And it noted that federal law does not require state-licensed pharmacies to report adverse events, so trouble linked to compounded versions is probably undercounted.
The agency's bottom line is deliberately narrow. Compounded drugs are meant for patients whose needs genuinely cannot be met by an approved product, prescribed and filled at a state-licensed pharmacy. They are not meant to serve as a routine, cheaper substitute for a medicine that has passed review.
A 2026 headline that is easy to misread#
Regulatory news about peptides keeps arriving, and the categories are easy to confuse. In April 2026, the FDA announced it would remove a group of peptides from Category 2 of its 503A bulk drug substances list and scheduled a Pharmacy Compounding Advisory Committee meeting to weigh whether some should be evaluated for the list.
Precision matters here. Removal from a "do not compound" category is not approval, is not placement on the authorized bulk-substances list, and is not permission to compound. An advisory committee's recommendation is non-binding, and any real change to what pharmacies may lawfully compound would still require formal notice-and-comment rulemaking. Naming a peptide in that setting describes its administrative status and says nothing about whether using it is safe or helpful.
The lesson worth keeping#
The GLP-1 episode is a clean illustration of a rule that outlasts this particular drug: access was governed by supply, not by the merits of a copy. A shortage listing suspended a prohibition, resolving the shortage restored it, and the enforcement-discretion deadlines gave the market a defined runway to stop. The next time a compounded version of a popular medicine appears in an ad, the useful question is not whether it exists or how much it costs, but which legal category it occupies, because that is what determines what has actually been checked.
Sources and further reading
Questions and answers
Were compounded GLP-1 drugs ever FDA-approved?
No. They were permitted only under the shortage exception. No compounded semaglutide or tirzepatide product has been reviewed or approved by the FDA for safety and effectiveness.
Does the wind-down mean compounding is banned entirely?
No. Traditional 503A compounding still exists for patients with a documented need an approved product cannot meet. What ended was mass-producing these drugs as copies of the brand-name versions, which was allowed only while the shortage listing was active.
How can I tell which category a product falls into?
Ask whether it is an FDA-approved product, a compounded preparation permitted only under specific conditions, or a substance with no approved status at all. Those three states carry very different guarantees, and a low price says nothing about which one you are looking at.