FDA logged 520 adverse event reports tied to compounded semaglutide by April 2025

The FDA had received 520 adverse event reports connected to compounded semaglutide by April 30, 2025, a count the agency cited as justification for the compounding enforcement deadlines that followed ^[1].

The numbers landed at the end of a regulatory shift. The FDA declared the semaglutide shortage resolved in February 2025, which removed the legal foundation that had allowed compounding pharmacies to produce the drug at scale during the shortage ^[1]. The agency then set two deadlines: April 22, 2025 for state-licensed 503A pharmacies and May 22, 2025 for 503B outsourcing facilities, both to stop compounding products that were "essentially a copy" of semaglutide ^[1]. The 520 reports, tallied by the end of April 2025, were cited as part of the urgency behind that timeline ^[1].

What the reports involved

A frequently reported problem was dosing error. Patients administered 5 to 20 times their intended dose after confusing units with mg/mL concentrations, according to the safety concerns described in the FDA data ^[1]. Compounded semaglutide is often supplied in multi-dose vials at varying concentrations, unlike the fixed-dose auto-injector pens used for Ozempic and Wegovy ^[1]. The 520 figure reflects only incidents that were reported and likely undercounts actual harm ^[1].

The FDA count covers compounded semaglutide generally and does not break out how many of the 520 reports involved serious outcomes, hospitalizations or deaths; that breakdown has not been reported ^[1]. The reports also came alongside safety signals about unapproved salt forms such as semaglutide sodium and semaglutide acetate, which are not FDA-approved and have not been evaluated for safety or effectiveness. Only semaglutide base is FDA-approved ^[1].

Cost was the backdrop. Compounded semaglutide typically cost patients between $150 and $400 per month, compared with $935 to $1,349 per month for brand-name Ozempic or Wegovy without insurance ^[1].

Enforcement continued after the deadlines

The crackdown widened over the following year. In March 2026, the FDA issued more than 50 warning letters to telehealth firms and compounding pharmacies in a single coordinated wave, described as the largest action against GLP-1 compounders in U.S. history ^[1]. On February 20, 2026, the FDA sent a warning letter to Join Josie citing false or misleading claims ^[1]. Major telehealth platforms including Hims and Ro exited compounded semaglutide entirely after enforcement attention and a Department of Justice referral in early 2026 ^[1].

On April 30, 2026, the FDA formally proposed removing semaglutide and tirzepatide from the 503B Bulk Drug Substances List, opening a public comment period through June 29, 2026 ^[1]. Industry analysts widely expect the ban to be finalized in the third quarter of 2026, which would effectively end 503B production of compounded semaglutide ^[1]. The proposal does not eliminate the 503A pathway ^[1].

Why it matters for patients

For patients who used compounded semaglutide, the practical situation depends on where the product came from. A 503A state-licensed pharmacy can still compound semaglutide for an individual patient with a documented clinical need, such as an allergy to an inactive ingredient in the brand-name product or a need for a dosage form that is not commercially available ^[1]. That standard requires clinical documentation from a licensed prescriber; cost alone is not a recognized basis for 503A compounding ^[1].

The 520 reports also point to a risk that does not disappear with the regulatory deadlines. Concentration confusion between units and mg/mL is a documented problem with multi-dose vials, and patients moving between compounded and brand-name products are described as being at particular risk during the adjustment period ^[1].

What has not been disclosed is a full public accounting of the 520 reports, including how many were serious and what products or pharmacies they involved ^[1].

What happens next

The public comment period on the proposal to remove semaglutide and tirzepatide from the 503B Bulk Drug Substances List runs through June 29, 2026 ^[1]. A final rule is widely expected in the third quarter of 2026 ^[1]. Separately, the FDA issued a policy clarification on compounding exemptions on April 1, 2026, which legal analysts note does not carry the force and effect of law but signals enforcement intent ^[1].