Thousands of lawsuits, including at least 4,000 consolidated claims, allege GLP-1 drugs such as Ozempic, Wegovy, Zepbound and Trulicity have caused vision loss, with a recent wave focused specifically on nonarteritic anterior ischemic optic neuropathy, according to a Sept. 21 USA Today report.
Here are six things to know:
- NAION is a rare condition that causes sudden, often permanent vision loss in one or both eyes. Sometimes called an “eye stroke,” the condition is caused by disrupted blood flow to the optic nerve. It typically affects people 50 and older, with an incidence of two to 10 cases per 100,000 people annually in that age group, according to the American Academy of Ophthalmology.
- Plaintiffs allege Eli Lilly and Novo Nordisk knew or should have known about the risk of NAION and failed to warn patients. Nearly 100 NAION-specific lawsuits have been filed in New Jersey since 2025, with another cluster in Philadelphia. Novo Nordisk and Lilly have disputed a significant link and noted that patients with diabetes already face an elevated baseline risk of vision complications.
- Research remains mixed. A 2024 Mass General Brigham and Harvard Medical School study and a 2025 study in Diabetes, Obesity and Metabolism found an association between semaglutide and NAION but did not establish causation. Other studies, including a Novo Nordisk-funded study from earlier this year, found no association.
- Novo Nordisk added a NAION warning to European labels for Wegovy and Ozempic in June, stating the condition may occur in up to 1 in 10,000 patients. The warning also appears on labels in the U.K., EU, Denmark and Australia, but not in the U.S. The American Academy of Ophthalmology has said current evidence does not support a blanket U.S. warning.
- NAION is not the only eye condition studied in connection with GLP-1s. A 2025 study found semaglutide users had a higher risk of neovascular age-related macular degeneration, and the American Academy of Ophthalmology and North American Neuro-Ophthalmology Society have said semaglutide may also worsen diabetic retinopathy, causing macular complications and blurry vision. A 2024 study first drew wide attention to a possible NAION association, and a follow-up study later that year also found an association.
- The NAION litigation adds to a broader wave of GLP-1 lawsuits, including consolidated claims alleging gastrointestinal injuries such as gastroparesis and intestinal obstruction, as drugmakers continue defending the safety profiles of the medications.
