FDA tallies more than 1,700 adverse event reports naming compounded GLP-1s
FDA has logged 990 adverse event reports tied to compounded semaglutide and more than 730 tied to compounded tirzepatide through May 31, 2026 — totals the agency says are likely undercounts.
The FDA has now received more than 1,700 adverse event reports involving compounded GLP-1 drugs, according to agency data current through May 31, 2026. The count includes 990 reports associated with compounded semaglutide and more than 730 associated with compounded tirzepatide [1].
The agency cautions that these reports do not establish that the compounded products caused the problems described. But it also says the totals are likely undercounts, because many state-licensed pharmacies — so-called 503A pharmacies — are not required to report adverse events at all [1]. That means the real number of problems tied to these products is not known.
Separately, America's Poison Centers reports it managed 22,966 GLP-1 agonist exposure cases from 2019 through 2025, with call volume rising nearly 1,500% over that period. Most of those cases involved accidental therapeutic errors with FDA-approved drugs. Compounded products, however, have been linked to 10-fold dosing mistakes caused by confusion over syringe measurement units [1].
A market that did not disappear
Compounded copies of semaglutide (the drug in Ozempic, Wegovy and Rybelsus) and tirzepatide (Mounjaro and Zepbound) became widely available during national shortages. FDA added Wegovy to its shortage list in March 2022, Ozempic that August and tirzepatide in December 2022. Those listings opened a narrow legal path for pharmacies to sell copies of drugs still under U.S. patent [1].
Those shortages are over. FDA declared the tirzepatide shortage resolved in December 2024 and the semaglutide shortage resolved in February 2025, and the last enforcement discretion window closed on May 22, 2025 [1]. Even so, the market has persisted. Novo Nordisk estimated in January that as many as 1.5 million Americans were still using compounded GLP-1s, and a study published in JAMA Health Forum this summer described the post-shortage market as "robust," identifying 75 clinics and medical spas offering compounded GLP-1s in Oklahoma and West Virginia alone [1].
FDA enforcement has continued in waves. The agency sent more than 55 warning letters to online sellers in a single day in September 2025, 30 more in February 2026 (announced in March) and 25 more in June, citing misbranding under sections 502(a) and 502(n) of the federal drug law [1].
Labeling and sales-model complaints
Beyond adverse events, FDA has warned that some compounded semaglutide and tirzepatide products carry false label information, including pharmacy names that either do not exist or did not actually make the drug [1].
Complaints also extend to how the products are sold. Customers of the telehealth sellers FitRx and Zealthy have described poorly disclosed charges, recurring subscriptions and obstructed cancellations, including an $866 charge that a WIRED contributor disputed after registering simply to check the price of compounded tirzepatide [1].
A pending civil RICO complaint names the telehealth infrastructure companies OpenLoop Health and Triad Rx, alleging they operated the back end for a network of consumer-facing storefronts selling oral tirzepatide, and that the formulation has no demonstrated oral absorption or efficacy. Eli Lilly does not market an oral tirzepatide product [1]. In February 2026, FDA issued a warning letter to MEDVi, alleging that branding compounded semaglutide and tirzepatide under the company's own name obscured the products' actual source and misleadingly implied equivalence to FDA-approved drugs. MEDVi said it never received the letter and that it was directed at an affiliate [1].
Why it matters for patients
Compounded GLP-1s are not FDA-approved. That means no agency has reviewed the specific product's strength, purity or labeling before it reaches a patient. The reporting gap matters here: because 503A pharmacies face no mandatory reporting duty, a patient who has a bad reaction may find that the event never enters any federal database [1].
The dosing-error pattern flagged by poison centers is specific and practical. Compounded products are often shipped in vials with separate syringes, and confusion over units on those syringes has produced 10-fold overdoses [1]. That risk profile differs from prefilled pens used with approved products.
FDA's warnings about false pharmacy names on labels also mean a buyer may not be able to verify who actually made the drug in the vial [1]. And the billing complaints suggest cost is not always what it appears at signup [1].
What happens next
The bipartisan SAFE Drugs Act of 2025 would limit 503A compounding of a drug that is "essentially a copy" of a commercially available product to no more than 20 times per month, unless a prescriber deems a patient-specific change significantly different. As of August 2026, the bill remains before the House Energy and Commerce Committee, with the Alliance for Pharmacy Compounding and the National Community Pharmacists Association opposing the 20-unit cap and added reporting requirements [1].
Litigation is also unresolved. The Outsourcing Facilities Association sued FDA in late 2024 over both shortage determinations, arguing the agency moved too fast in declaring them over. Novo Nordisk says it has filed 132 suits across 40 states and won 44 permanent injunctions; Lilly sued the compounders Strive Pharmacy and Empower in April 2025, then four telehealth companies weeks later [1].
Sources
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