GLP-1 compounding policy: the legal mechanics

The dated sequence of events, from the 2022 shortages to the 2026 warning letters, is on our FDA and compounded GLP-1s page. This page explains the law underneath it: why compounders could make semaglutide and tirzepatide at all, what changed when the shortages ended, and how the rules differ for the two kinds of compounder.

Two kinds of compounder, two sets of rules

Why the shortage mattered

Semaglutide and tirzepatide are components of approved drugs, so a 503A pharmacy may in principle use them. The limit is on copying. A 503A pharmacy may not compound "regularly or in inordinate amounts" drugs that are essentially copies of a commercially available drug, and a drug on FDA's shortage list is not treated as commercially available. A 503B facility may compound from a bulk ingredient only if it is on the 503B list or the drug is on FDA's drug shortage list. When Wegovy, Ozempic, Mounjaro and Zepbound were listed in 2022, both routes opened. When FDA declared the shortages resolved, on 19 December 2024 for tirzepatide and 21 February 2025 for semaglutide, both closed, after grace periods ending in early 2025.

The 503A rule after the shortage

FDA's clarification of 1 April 2026 set out how it reads "essentially a copy" for GLP-1s. A compounded product is a copy if it has the same active ingredient in the same, similar or easily substitutable strength and can be used by the same route as the approved product. 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. It gave an example: semaglutide combined with vitamin B12 is still a copy if each strength is within 10% of the approved product's.

The 503B list proposal

On 1 May 2026 FDA published a Federal Register notice (91 FR 23431, docket FDA-2018-N-3240) identifying three bulk drug substances it "has considered and proposes not to include on the 503B Bulks List: semaglutide, tirzepatide, and liraglutide." The original comment deadline of 30 June 2026 was extended to 30 July 2026 at a commenter's request. As of 15 October 2026 FDA had not published a final decision. If finalised, outsourcing facilities would be able to compound these drugs from bulk again only if they returned to the shortage list.

Ingredient supply and marketing

On 6 February 2026 FDA said it intended "to take decisive steps to restrict GLP-1 active pharmaceutical ingredients" intended for non-approved compounded drugs that are being mass-marketed, and that companies "cannot claim that non-FDA-approved compounded products are generic versions" of approved drugs. The Alliance for Pharmacy Compounding's chief executive responded the same day: "What authority does FDA have to restrict compounding with a particular API," noting FDA had not claimed the compounded ingredient differed from the approved one.

Research-labelled GLP-1s are a separate matter

Products sold online as "research" semaglutide, tirzepatide or retatrutide are not compounded drugs at all. FDA treats them as unapproved new drugs and has sent warning letters to sellers, including Gram Peptides in March 2026 and Peak Performance Peptides in August 2026. Retatrutide is not approved in any form; see retatrutide. Ohio's Board of Pharmacy names research-labelled retatrutide, cagrilintide, semaglutide and tirzepatide among products it has found at clinics, and says they "must be disposed of immediately". The enforcement page has the detail.

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, including reports linked to dosing errors. Adverse event reports show that an event was reported, not that the product caused it. 503A pharmacies are not required to report adverse events to FDA, so these counts depend on voluntary reports.

Other regulators

• FTC: its July 2025 case against telehealth firm NextMed alleged hidden costs and unsupported weight-loss claims for a GLP-1 programme. It settled for $150,000 in refunds.
• WADA: GLP-1 drugs are not prohibited in sport, and WADA said in September 2026 their status will remain unchanged for 2027. See WADA and peptides.

For patients

Approved products are no longer in shortage, and both manufacturers sell direct at self-pay prices; see GLP-1 costs. Patient-specific compounding still exists where a prescriber documents a clinically significant difference. A compounded dose in units or millilitres does not always map neatly onto a pen dose in milligrams, so any switch is a prescriber's decision; the semaglutide reconstitution page explains the arithmetic, and the compounded glossary entry defines the terms.

If you change product or pharmacy, a record of each dose, the product and its concentration makes the switch easier to plan. The dose log and vial tracker keep that on one timeline with side effects and weight, and bloodwork can sit alongside it. The app is on iOS and Android.