Patients have filed dozens of lawsuits against Novo Nordisk and Eli Lilly, the makers of popular GLP-1 weight-loss and diabetes drugs, alleging the companies failed to adequately warn users about the risk of sudden vision loss from a condition called non-arteritic anterior ischemic optic neuropathy, or NAION.

The suits, which have been consolidated into a multidistrict litigation in the U.S. District Court for the Eastern District of Pennsylvania, claim that drugs including Ozempic, Wegovy, Mounjaro, and Zepbound caused permanent vision damage. As of early September 2026, 216 such cases were pending in the federal MDL, with additional complaints filed in state courts.

Plaintiffs say they experienced sudden, often irreversible vision loss in one or both eyes after using the medications. They accuse the manufacturers of knowing or should have known about the potential link and of prioritizing marketing over safety information. One complaint described the companies' efforts as an attempt to portray the drugs as "magic pills."

Evidence linking GLP-1 drugs to NAION remains mixed. A 2024 Harvard study found patients prescribed semaglutide faced more than four times the risk of NAION compared with those on other treatments. Other research has shown smaller increases or no significant association. European regulators updated labels in 2025 to note the risk occurs in up to one in 10,000 patients, but U.S. labels have not added a specific NAION warning. The American Academy of Ophthalmology has stated that available data do not support a blanket warning and that shared decision-making with physicians is appropriate.

The FDA is reviewing the potential connection. NAION is rare overall, and shares risk factors with many patients who take GLP-1 drugs, including diabetes, high blood pressure, and obesity.

Separate litigation over gastrointestinal side effects from the same class of drugs continues in the same court. No trials have resolved the vision-loss claims, and the companies maintain that the medications are safe and effective.