Full Breakdown
GLP-1 Drug Lawsuits Alleging Rare Vision-Loss Condition
By Drooid · · How we work
Core Event: Lawsuits Claim GLP-1 Medications May Trigger NAION
Hundreds of consumers have filed civil actions in New Jersey, Pennsylvania and other states alleging that GLP-1 receptor agonists—including Ozempic, Wegovy, Mounjaro, Zepbound and Trulicity—caused non-arteritic anterior ischemic optic neuropathy (NAION), a sudden and often permanent loss of vision.
Background & Context
GLP-1 drugs are approved for type-2 diabetes and obesity and have demonstrated cardiovascular and weight-loss benefits. NAION, described by the American Academy of Ophthalmology as an “eye stroke,” is the most common acute optic-nerve injury in adults over age 50, occurring at an estimated 2–10 cases per 100,000 people each year. Established risk factors include age, diabetes, hypertension, high cholesterol, obstructive sleep apnea and smoking—conditions frequently present in patients prescribed GLP-1 therapies.
Data & Statistics
- An observational analysis of 37 million adults published in *JAMA Ophthalmology* (2025) reported a modest increase in NAION risk for semaglutide users compared with SGLT2-inhibitor users.
- A Harvard Medical School study (2024) found roughly a fourfold higher relative risk of NAION among semaglutide patients, though the absolute risk remained very low.
- The European Medicines Agency (2025) classified NAION as a “very rare” adverse reaction to semaglutide, estimating occurrence in up to 1 in 10,000 treated individuals.
- The U.S. Food and Drug Administration is reviewing the evidence but has not issued a safety warning or added NAION to U.S. labeling.
- Multidistrict litigation (MDL #3163) consolidates the lawsuits in the Eastern District of Pennsylvania, with Judge Karen Spencer Marston presiding.
Official Statements & Responses
- Novo Nordisk called the suits meritless and cited company-funded research that found no increased NAION risk.
- Eli Lilly said it continuously monitors safety data and maintains that current studies do not prove the drugs cause NAION.
- FDA has stated it has not concluded that semaglutide causes NAION and has not added a label warning.
- EMA added NAION as a very rare side effect to semaglutide product information in Europe.
- Dr. Douglas Lazzaro, ophthalmologist at NYU Langone Health, noted the lack of treatment for NAION and advised clinicians to consider a “disc at risk” when prescribing semaglutide.
Conflicting Reports & Gaps
- Studies cited by plaintiffs (2024 Harvard, 2025 *JAMA* analysis) suggest an association between semaglutide and increased NAION risk.
- Other investigations, including a Novo-funded trial and two independent studies, reported no statistically significant link.
- All cited research is observational, limiting the ability to establish causation, and diabetes itself is a known NAION risk factor, complicating attribution.
- Evidence regarding tirzepatide and dulaglutide remains limited.
Verbatim Quotes
- “The problem with NAION is there’s no treatment,” — Dr. Douglas Lazzaro, NYU Langone Health
What's Next
- The FDA’s ongoing review may result in label modifications if a causal relationship is established.
- The MDL proceedings will continue through discovery, with potential settlement discussions under Judge Marston’s oversight.
- European regulators are expected to keep monitoring post-marketing data and adjust labeling as new evidence emerges.
