The FDA and compounded GLP-1s: what happened, in order

Compounded semaglutide and tirzepatide became widely available because of a specific legal exception, and most of what has happened since follows from that exception closing. This page sets out the sequence using FDA's own statements, orders and Federal Register notices. It is not legal advice, and the rules for any individual pharmacy or prescriber depend on facts this page does not have.

Why compounding was allowed in the first place

Federal law generally stops pharmacies from compounding drugs that are "essentially copies" of an approved, commercially available drug. One of the exceptions is a drug on FDA's shortage list. Two types of compounder matter here: state-licensed pharmacies operating under section 503A, which compound for individual prescriptions, and outsourcing facilities registered under section 503B, which can make larger batches. The compounded glossary entry explains both. When semaglutide and tirzepatide went on the shortage list, both kinds of compounder could make copies. When they came off, that permission ended, after a grace period.

The timeline

What FDA has said, in its own words

On marketing. The February 2026 statement says companies "cannot claim that non-FDA-approved compounded products are generic versions" of approved drugs, and may not claim they contain the same active ingredient or are clinically proven. The September 2025 letters cited claims such as "Semaglutide (the same ingredient in Wegovy & Ozempic)" and "TIRZEPATIDE (GENERIC MOUNJARO)". FDA's stated aim is to protect consumers "from drugs for which the FDA cannot verify quality, safety, or efficacy".

On what a 503A pharmacy may still do. The April 2026 clarification treats a compounded GLP-1 as an essential copy if it has the same active ingredient in the same, similar or easily substitutable strength and the approved product can be used by the same route. It is not a copy if the prescriber determines and documents a change that makes a significant difference for an identified patient. FDA said it does not intend, at this time, to act against a 503A compounder that fills four or fewer prescriptions of an essential copy in a calendar month. The same statement gives an example: semaglutide combined with vitamin B12 is still treated as a copy when the route is the same and each strength is within 10% of the approved product's.

On 503B facilities. Outsourcing facilities may compound from bulk ingredients only if the substance is on the 503B bulks list or the drug is in shortage. FDA noted in April 2026 that semaglutide and tirzepatide are on neither. The May 2026 proposal would make that permanent for semaglutide, tirzepatide and liraglutide. As of this writing, the notice is a proposal, not a final decision.

On safety reports. FDA's page on unapproved GLP-1 drugs, current as of 1 October 2026, says that as of 31 May 2026 it had received 990 adverse event reports associated with compounded semaglutide and more than 730 associated with compounded tirzepatide. It describes reports, some involving hospitalisation, that may relate to dosing errors with compounded injectable semaglutide, both by patients measuring doses and by clinicians miscalculating them. Adverse event reports show that an event was reported, not that the product caused it.

The other side of the argument

Compounders have contested parts of this. After the February 2026 statement, the Alliance for Pharmacy Compounding's chief executive asked, "What authority does FDA have to restrict compounding with a particular API," and noted that FDA had not claimed the compounded ingredient differs from the one in approved drugs. The courts have so far declined to block FDA's shortage decisions. The policy questions are still being argued.

What it means for patients now

• Approved products are not in shortage. Wegovy, Ozempic, Zepbound and Mounjaro are available through pharmacies, and both manufacturers sell direct at self-pay prices. See the costs page.
• Patient-specific compounding still exists where a prescriber documents a clinically significant difference for that patient. Ask your prescriber what the documented reason is.
• Switching products is a dose question. A compounded dose in units or millilitres does not always map neatly onto a pen dose in milligrams. The prescriber sets the new dose; the semaglutide reconstitution page explains the arithmetic.
• Ask direct questions. The provider guide has a list, including whether a product is FDA-approved or compounded and which pharmacy prepares it.

Whatever you are on, a log of each dose, the product and the concentration makes any switch safer to plan. Peptide AI records doses, vials and side effects on one timeline, free; the free GLP-1 tracker page has the detail.