The U.S. Food and Drug Administration (FDA) has issued a warning letter to pharmaceutical company Novo Nordisk after investigators found that the company failed to report certain suspected adverse drug reactions linked to its medicines within the required timeframe. The medicines include widely used glucagon-like peptide-1 (GLP-1) receptor agonists such as semaglutide and liraglutide, which are marketed under brand names including Ozempic, Wegovy, Saxenda, and Victoza for the treatment of type 2 diabetes and obesity.
The warning follows an FDA inspection that identified deficiencies in the company’s systems for monitoring and reporting post-marketing safety events.
The FDA issued the warning letter on March 5, 2026 after conducting a pharmacovigilance inspection at Novo Nordisk’s facility in Plainsboro, New Jersey between February and March 2025. The inspection evaluated the company’s post-marketing adverse drug experience reporting system, which pharmaceutical manufacturers must maintain to track safety issues once medicines are available to the public.
According to the agency, Novo Nordisk did not consistently submit serious and unexpected adverse event reports within the required timeframe. Under FDA regulations, companies must report serious and unexpected adverse drug experiences within 15 calendar days of becoming aware of the event so that regulators can assess potential risks associated with medicines already in use.
The FDA stated that investigators identified multiple instances where the company did not submit reports on time or failed to properly investigate adverse event information. The agency also noted problems in the company’s procedures for identifying reportable events and ensuring that follow-up information was obtained and submitted. The FDA also cited deficiencies in documentation practices and internal procedures used to identify and process reportable adverse events.
The warning letter and related reports highlighted several serious medical incidents associated with GLP-1 drugs that were not reported within the required timeframe.
One case involved a patient who died by suicide while taking semaglutide. The FDA stated that the company did not submit the report within the mandated reporting window. Another case involved a patient who experienced a disabling stroke that was potentially associated with liraglutide. According to the agency, the event was not reported properly because it was incorrectly categorized in the company’s safety system.
The FDA said such delays in reporting can hinder the agency’s ability to identify potential safety signals and respond appropriately.
After a drug receives regulatory approval, manufacturers must continue monitoring its safety through pharmacovigilance systems. Healthcare professionals, patients, and pharmaceutical companies report adverse events to the FDA so that regulators can detect rare or unexpected side effects that may not appear during clinical trials.
GLP-1 receptor agonists such as semaglutide and liraglutide mimic a hormone involved in glucose metabolism. They stimulate insulin secretion, reduce glucagon release, slow gastric emptying, and help control appetite. These actions help lower blood glucose levels and support weight reduction.
Several Novo Nordisk products containing these active ingredients are widely prescribed worldwide for type 2 diabetes and obesity management. Due to their widespread use, regulators emphasize the importance of accurate and timely reporting of potential safety concerns.
Novo Nordisk acknowledged receiving the warning letter and stated that it is cooperating with the FDA to address the concerns identified during the inspection. The company said it has already taken steps to improve its safety reporting systems and submitted updates describing corrective actions.
The company also stated that the FDA warning letter does not question the safety, effectiveness, or quality of its approved medicines.
According to the FDA, Novo Nordisk must outline additional corrective actions and ensure that its pharmacovigilance systems comply with federal adverse event reporting requirements.
See more: UK Woman Nearly Dies After Injecting Fake Ozempic Bought on Facebook
Regulatory scrutiny of GLP-1 drugs has increased in recent years due to the rapid growth in their use for diabetes and weight management. Millions of patients worldwide use these medicines, which makes ongoing safety monitoring essential.
The FDA relies on adverse event reports from pharmaceutical companies as part of its post-marketing surveillance system. These reports allow regulators to detect safety signals, investigate potential risks, and update prescribing information or issue safety communications when needed.
The agency stated in the warning letter that pharmaceutical companies must maintain systems capable of identifying, evaluating, and reporting adverse drug experiences promptly. The agency emphasized that timely adverse event reporting is essential for detecting potential safety risks and protecting public health.
1. U.S. Food and Drug Administration. “Novo Nordisk Inc. Warning Letter (717576).” March 5, 2026.
https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/novo-nordisk-inc-717576-03052026
(Rh/MSM)
