Novo Nordisk, the pharmaceutical company behind Ozempic, has received a warning letter from the U.S. Food and Drug Administration over issues with its procedures for reporting potential side effects of the flagship diabetes drug, which is also prescribed for weight loss. 

In the letter, dated March 5, the FDA cited three deaths among patients receiving semaglutide, the generic name for the medication in Novo Nordisk’s Ozempic and Wegovy, which were allegedly not reported properly to the agency. Those deaths included one suicide, according to the FDA. Another instance involved a patient that reported suicidal ideations while taking semaglutide.

The FDA did not speculate as to whether the deaths or other side effects were necessarily linked to the medication. Its letter focused on the fact that Novo Nordisk apparently violated its protocols for reporting adverse symptoms that could potentially be tied to the drug. 

FDA investigators discovered problems with Novo Nordisk’s reporting compliance when it conducted an inspection at the Danish drugmaker’s U.S. headquarters in Plainsboro, New Jersey, in early 2025. It was conducted as part of the agency’s Bioresearch Monitoring Program, which aims to ensure that accurate and timely information about product safety is submitted to the FDA for monitoring.

Novo Nordisk responded to the FDA’s warning letter on Tuesday, saying in a statement that it had been “working diligently” to address the agency’s concerns since its inspection took place last year. The company said the letter largely sought more details about the steps the company has taken since the inspection to comply with post-marketing adverse drug experience, or PADE, regulations. But the letter did not “make any conclusions about the quality or safety of our medicines,” the company said.

“Novo Nordisk takes PADE reporting requirements seriously and we plan to address the requests in the Warning Letter expeditiously and holistically,” said Anna Windle, the head of clinical development, medical and regulatory affairs at Novo Nordisk U.S. “We are confident that we will resolve the matters outlined in Warning Letter to the FDA’s full satisfaction.”

Another recent evaluation by the FDA determined that there was no connection between suicide and GLP-1 drugs such as Ozempic or Wegovy. The agency in January requested the removal of boxed warnings for suicidal behavior or ideation from those medications.