The Food and Drug Administration is warning that popular obesity drugs—including Ozempic, Wegovy, Zepbound, and Mounjaro—may carry a potential increased risk of a rare eye condition that can lead to permanent vision loss.
In a drug safety communication, the FDA announced it will now require manufacturers of GLP-1 receptor agonist medications to include a warning about this risk on their product labels. The condition, known as non-arteritic anterior ischemic optic neuropathy or NAION, stems from restricted blood flow to the optic nerve. This restriction causes swelling and cell death that ultimately damages the nerve, leading to sudden vision loss that is frequently permanent.
The exact mechanism by which GLP-1 drugs might cause NAION remains unknown. The American Academy of Ophthalmology notes that the condition is rare in the general population, affecting between two and 10 people per 100,000, which complicates efforts to confirm a definitive connection. Establishing a clear link is further challenged because standard risk factors for NAION—such as diabetes, cardiovascular disease, high blood pressure, high cholesterol, metabolic syndrome, and obstructive sleep apnea—are also prevalent among patients prescribed GLP-1 medications.
Study Findings and Limitations
Initial research pointing to a connection between GLP-1 medications and NAION emerged in 2024 from investigators at Harvard University. Published in JAMA Ophthalmology, the study evaluated 710 patients diagnosed with diabetes and 979 patients classified as overweight or obese. Across both categories, some individuals received semaglutide, marketed as Ozempic and Wegovy, while others used non-GLP-1 treatments for diabetes or weight loss. The investigators observed that participants using GLP-1 drugs over a 36-month period experienced higher rates of NAION in both patient groups. Specifically, 8.9 percent of diabetes patients taking semaglutide developed the eye condition compared to 1.8 percent of those in the comparison groups. In the overweight and obese cohort, 6.7 percent of patients on a GLP-1 developed NAION versus 0.8 percent of the non-GLP-1 group.
However, the study featured notable limitations. All participants came from a single referral center that handled the majority of NAION cases in that region. Furthermore, the overall incidence rates of NAION among the study participants far exceeded those observed in the general population, indicating potential selection bias and limiting the generalizability of the findings. The research also failed to account for the severity of diabetes among patients, a factor that can impact NAION risk, and did not identify how GLP-1 drugs might contribute to the condition.
