Compounded and Counterfeit GLP-1 Drugs

US law permits pharmacy compounding of a drug that is on the FDA shortage list, and when semaglutide and tirzepatide entered shortage in 2022 under unprecedented demand, that clause turned a niche practice into an industry: compounding pharmacies and telehealth platforms sold copies at a fraction of branded prices, entirely legally. The window closed on schedule — tirzepatide left the shortage list in December 2024, semaglutide in February 2025, and after a court refused the compounding trade association an injunction, large-scale compounding of semaglutide lost its legal basis on 22 May 2025. Everything sold through those channels since is either operating in a claimed loophole or simply illegal — a distinction that matters to lawyers and not at all to the patient injecting the product.

After the deadline, parts of the industry pivoted rather than stopped. Some compounders invoked 'personalised dosing' — adding vitamins or unusual strengths to claim the copy is not a copy; others sold semaglutide salt forms (sodium, acetate) that have never been tested in humans and are not the approved active ingredient; telehealth sellers kept advertising. The FDA answered with more than 55 warning letters to sellers in September 2025, another 30 to telehealth companies in early 2026 after reviewing their websites, and — the structural move — an April 2026 proposal to exclude semaglutide, tirzepatide and liraglutide from the 503B bulk substances list permanently, closing the last legal pathway regardless of future shortages. Novo Nordisk's lawsuits against major telehealth players, including over a compounded semaglutide tablet launched in 2026, run in parallel.

By April 2025 the FDA had logged over 520 adverse-event reports for compounded semaglutide and over 480 for compounded tirzepatide — undercounts by construction, since compounded products carry no manufacturer pharmacovigilance. The dominant harm is prosaic: dosing error. Branded products come in fixed-dose pens; compounded versions ship as multidose vials with syringes, and patients have drawn up five- and ten-fold overdoses, some requiring hospitalisation for intractable vomiting and hypoglycaemia. Beyond dosing sit the compounding-specific risks — sterility, potency variation, unverified ingredient sourcing from overseas chemical suppliers — none of which implies every compounded dose was harmful, and all of which explains why the products were never a like-for-like substitute.

Distinct from compounding — which is at least performed by licensed pharmacies — is outright falsification. Counterfeit Ozempic has been seized inside the legitimate US supply chain, prompting FDA lot-number alerts, and the WHO issued a global alert after falsified batches surfaced on three continents. The most dangerous variant is the relabelled insulin pen: fake 'Ozempic' that is actually fast-acting insulin has hospitalised buyers with severe hypoglycaemia in multiple countries. Social-media marketplaces, unlicensed 'med spas' and research-chemical websites are the distribution layer. The verification basics — buy only through licensed pharmacies, check lot and serial numbers against manufacturer databases, distrust any pen sold without a prescription — are unglamorous and decisive.

The shadow market was demand-driven arithmetic: branded GLP-1s cost hundreds to over a thousand dollars monthly in the US, insurance coverage for obesity treatment was patchy, and the shortage made even willing payers go without. Compounded copies at a tenth of the price were a rational gamble for many patients, and moralising about it misses the access failure that created the market. The landscape has since shifted: manufacturer savings programmes expanded, an approved oral semaglutide launched in 2026, direct-to-patient government pricing channels appeared, and prices have come under real pressure. The market that made compounding rational is shrinking — which, more than any warning letter, is what will end it.

A GLP-1 sourced anywhere other than a licensed pharmacy dispensing an approved product is now an unregulated gamble: post-deadline compounded versions have no legal basis and no quality oversight, salt-form products are untested molecules, and counterfeit pens have contained insulin. Anyone currently using a compounded product should not stop abruptly for fear of legality — obesity treatment interruption has its own costs — but should transition to an approved product through a prescriber, using the manufacturer affordability programmes that now exist. And any seller who does not require a prescription has answered the quality question already.