WASHINGTON — Federal regulators on Monday ordered manufacturers of popular GLP-1 medications to update their warning labels after an agency safety review identified an increased risk of a rare eye condition that can lead to permanent blindness.
The U.S. Food and Drug Administration directed drugmakers behind Ozempic, Wegovy, Mounjaro, Zepbound and Soliqua to add information regarding nonarteritic anterior ischemic optic neuropathy, commonly known as NAION, to the Warnings and Precautions section of their product labels, The Guardian reported.
Review of Clinical Trial Data
NAION develops when blood vessels supplying the optic nerve become obstructed, depriving nerve tissue of oxygen, according to the FDA. The disorder causes sudden, painless vision loss in one eye, and there is currently no approved medical treatment to reverse the damage. NAION remains the leading cause of acute optic nerve injury among adults older than 50, typically occurring in 2.3 to 10.2 individuals per 100,000 in that age group annually.
The FDA launched its safety inquiry following a 2024 study in JAMA Ophthalmology that identified an elevated incidence of the eye disorder among patients prescribed GLP-1 drugs. Researchers behind a previous two-year-old study of 17,000 patients observed that individuals on semaglutide were four times more likely to receive a NAION diagnosis, though lead author Dr. Joseph Rizzo of Harvard Medical School described those conclusions as significant yet tentative, BBC News reported.
Following an evaluation of 126 clinical trials comprising more than 134,200 individuals, the FDA discovered 15 probable occurrences of NAION. Ten of those occurred among patients receiving GLP-1 treatments, five involved patients on a placebo, and none were identified among participants taking other glucose-lowering drugs.
The agency determined the incidence rate was 6.4 cases per 100,000 person-years for patients on GLP-1 drugs, compared with 3.8 cases per 100,000 person-years among those taking placebos or alternative diabetes medications. The FDA noted that cases were reported across all currently marketed GLP-1 receptor agonist products.
Causation and Medical Guidance
Evaluating the link remains complicated because standard risk factors for NAION — including type 2 diabetes, high blood pressure, elevated cholesterol and smoking — overlap heavily with the conditions GLP-1 drugs treat, regulators said. The agency stated that it remains unknown why GLP-1 users might experience a higher risk.
Drugmaker Novo Nordisk, which manufactures Ozempic and Wegovy, pushed back against conclusions that the treatments directly trigger the eye disorder.
“Patient safety is a top priority for Novo, and we continue to monitor the safety of our medicines, review new research and work with health authorities around the world,” the company said in a statement to The Guardian, adding that it “continues to believe the data do not establish a cause-and-effect relationship.”
GLP-1 medications already carry packaging warnings for pancreatitis and gallbladder disease, while common side effects include nausea, vomiting and abdominal discomfort. Last year, the safety committee of the European Medicines Agency reported that as many as one in 10,000 patients on semaglutide could develop NAION.
Despite the label update, eye specialists cautioned patients against stopping their prescribed treatments abruptly.
“GLP-1 medications offer important benefits for people with diabetes, obesity, and heart disease, so our message to patients is simple,” the American Academy of Ophthalmology told BBC News in a statement. “Don’t stop your medication without talking to your doctor, and if you notice sudden, painless vision loss in one eye, see an ophthalmologist promptly.”
The academy noted that any added danger appears small and unproven as a direct result of the medications. Health officials continue to examine whether the link stems directly from the biological mechanisms of the drugs or underlying vascular conditions in the patient population.
