A growing number of lawsuits have been filed against Novo Nordisk and Eli Lilly, manufacturers of popular GLP-1 weight-loss drugs like Ozempic, Wegovy, Mounjaro, and Zepbound. These lawsuits allege that the drugs caused sudden and irreversible vision loss, specifically non-arteritic anterior ischemic optic neuropathy (NAION), often described as an eye stroke. At least 110 plaintiffs across federal and state lawsuits claim blindness as a side effect, and a multi-district litigation involving over 130 cases is currently before a judge in Philadelphia.
The plaintiffs contend that drug manufacturers were aware of the increased risk of NAION but failed to adequately warn patients. A 2024 study published in JAMA Ophthalmology by researchers at Mass Eye and Ear in Boston indicated that diabetic patients on GLP-1 medications were more than four times more likely to be diagnosed with NAION, while overweight patients had over seven times the risk. These legal challenges are distinct from the existing mass litigation concerning gastrointestinal side effects but will proceed before the same judge, U.S. District Judge Karen Marston, in Philadelphia federal court.
One plaintiff, Diane Wirth, a former nurse practitioner, began taking Wegovy in February 2025 and woke up weeks later unable to see out of her right eye. Diagnosed as legally blind in that eye, she described the experience as "heartbreaking, jarring, and angry," noting the absence of any warning signs or preventative measures for NAION. Another client, a 48-year-old gentleman from New York, lost sight in both eyes. The attorneys involved anticipate a significant increase in the number of lawsuits, which are expected to continue for several years.
The drug manufacturers, including Novo Nordisk and Eli Lilly, have broadly refuted the allegations and stated their intent to vigorously defend the safety of their drugs. However, the lawsuits underscore a critical concern for the over 31 million Americans estimated to be using GLP-1 drugs, highlighting the profound impact of unexpected side effects like permanent vision loss on individuals' lives and livelihoods.
While the current focus is on vision loss, these new lawsuits contribute to the broader legal challenges faced by GLP-1 drugmakers, with over 4,400 patients having filed lawsuits that are now part of consolidated federal and state litigation. The centralization of the blindness-related cases into a separate multi-district litigation in Philadelphia reflects the distinct nature of these injuries compared to the gastrointestinal side effects, although both will be overseen by Judge Marston.
