FDA Issues Warning Letter to Novo Nordisk Over Unreported Semaglutide Deaths and Systematic Pharmacovigilance Failures
The FDA cited Novo Nordisk for serious violations of adverse event reporting requirements after a 2025 inspection found the company failed to report three patient deaths linked to semaglutide, including one suicide, and lacked adequate procedures for post-marketing drug safety surveillance.
Overview
The U.S. Food and Drug Administration issued a warning letter to Novo Nordisk on March 5, 2026, citing “serious violations” of post-marketing adverse drug experience reporting requirements for semaglutide, the active ingredient in Ozempic and Wegovy. The letter, made public on March 10, followed an inspection of the company’s Plainsboro, New Jersey facility conducted between January 13 and February 7, 2025, which uncovered systemic failures in how the Danish pharmaceutical giant tracks and reports safety signals for its blockbuster GLP-1 receptor agonist drugs.
Three Unreported Deaths
The FDA documented three patient deaths associated with semaglutide use that Novo Nordisk failed to report within the required 15-calendar-day window. In one case, the company did not obtain consent from a non-healthcare professional who reported a patient death while receiving semaglutide and closed the case without submitting it to the agency. In another, a physician reported that a patient taking semaglutide experienced depression and died by suicide, but the company neither investigated nor reported the case as required. The FDA emphasized that it did not establish a causal link between semaglutide and the deaths, but federal law mandates reporting regardless of whether causation is confirmed.
Beyond the three deaths, inspectors identified at least ten additional serious adverse events that went unreported, including cases of stroke and suicidal ideation. Some reports were more than 800 days overdue.
Systemic Procedural Failures
The warning letter described problems that went beyond individual missed reports. The FDA found that Novo Nordisk’s own written procedures actively inhibited compliance with adverse event reporting rules. The company’s internal policy stated that follow-up was not required on reported adverse drug experiences if consent was not obtained from the reporter and the reporter was a non-healthcare professional, a standard the FDA characterized as inconsistent with federal regulations.
Inspectors also found that the company rejected cases based on reporters’ causality assessments rather than the FDA’s broader definition, invalidated cases by claiming missing patient identifiers when identifiers were actually available, and allowed cases to remain in “medical review” status beyond internal timelines without filing required reports. The violations spanned multiple products including semaglutide, liraglutide, nedosiran sodium, and estradiol, though semaglutide cases dominated the findings.
Company Response
Novo Nordisk has stated that it takes post-marketing adverse event reporting requirements seriously and plans to “address the requests in the warning letter expeditiously and holistically.” Anna Windle, the company’s head of clinical development, medical and regulatory affairs, expressed confidence that the company would resolve the matter to the FDA’s satisfaction. However, the FDA noted in the letter that Novo Nordisk’s most recent written response, submitted on January 15, 2026, “did not provide sufficient details” to determine whether the violations had been corrected.
The company has been given 15 business days from the letter’s issuance to outline corrective actions, including a comprehensive review of all pharmacovigilance-related deviations dating back to January 2021.
Regulatory Context
The warning letter arrives at a moment of heightened regulatory scrutiny for GLP-1 medications. Semaglutide has become one of the most widely prescribed drugs in the world, with Ozempic and Wegovy generating tens of billions of dollars in annual revenue for Novo Nordisk. The FDA’s enforcement action is not the company’s first regulatory setback in recent months: the agency previously cited Novo Nordisk for deceptive advertising practices in September 2025 and manufacturing violations in August 2025.
The FDA relies on complete and timely adverse event submissions to monitor drug safety profiles, a system that becomes especially critical as patient populations expand rapidly. With millions of patients now taking semaglutide-based medications for diabetes and weight management, gaps in safety surveillance carry outsized public health implications. The agency warned that failure to adequately address the deficiencies could result in further regulatory action.