The Zepbound blindness lawsuit is a growing product liability claim alleging that Eli Lilly’s weight loss and diabetes drug can cause a rare form of permanent vision loss called non-arteritic anterior ischemic optic neuropathy (NAION), and that the company failed to warn patients and prescribers about the risk. As of mid-2026, these claims are consolidated in a federal multidistrict litigation in the Eastern District of Pennsylvania, with 110 cases pending, no settlements reached, and no trial dates set.1MDL Update. MDL-3163 GLP-1 NAION Products Liability Litigation
The Injury Behind the Lawsuits
NAION is sometimes called an “eye stroke.” Blood flow to the optic nerve is suddenly reduced or cut off, and the resulting nerve damage causes rapid, painless vision loss, usually in one eye. Patients often notice the loss on waking: a dark shadow or blur across the upper or lower half of the visual field, blurred or foggy vision, faded colors, or sensitivity to light. The vision loss is typically permanent.2Seeger Weiss LLP. GLP-1 NAION Vision Loss Lawsuit
The American Academy of Ophthalmology calls NAION the second most common form of optic neuropathy and a significant cause of blindness in adults.3American Academy of Ophthalmology. Glucagon-Like Peptide-1 Receptor Agonists and Risk of NAION People with diabetes, obesity, high blood pressure, sleep apnea, and a particular optic nerve anatomy known as a “disc at risk” already have a higher baseline risk of NAION regardless of what medications they take.4American Journal of Ophthalmology. GLP-1 Receptor Agonists and Risk of NAION Those are also the same patients who are prescribed Zepbound, and that overlap sits at the center of the legal fight.
What the Lawsuits Allege Against Eli Lilly
The core theory is failure to warn. Plaintiffs contend that Eli Lilly knew or should have known about the NAION risk and failed to include adequate warnings on the Zepbound label or in communications with doctors and patients.5Motley Rice LLC. Eli Lilly Diabetes Lawsuits The original Zepbound label, approved in November 2023, contains no mention of NAION or vision loss as a risk.6FDA. Zepbound Prescribing Information
Plaintiffs allege they took Zepbound (or the related tirzepatide product Mounjaro) and subsequently developed NAION, causing sudden and permanent blindness in one or both eyes. Similar claims have been brought against Novo Nordisk, which makes the semaglutide products Ozempic, Wegovy, and Rybelsus, and both manufacturers are named as defendants in the consolidated federal proceeding.
An illustrative case from the broader litigation involves a 62-year-old Maryland man prescribed Ozempic for diabetes in 2023. According to his April 2025 lawsuit, he was diagnosed with NAION four months after starting the medication and alleges he is now blind in both eyes and unable to work.7Motley Rice LLC. Ozempic Lawsuits
The Scientific Evidence in Dispute
The research on GLP-1 drugs and NAION cuts in both directions, and no study has definitively established causation.
The study that launched the litigation was a July 2024 retrospective analysis in JAMA Ophthalmology from Massachusetts Eye and Ear and Harvard Medical School. Examining nearly 17,000 patients over six years, the researchers found a hazard ratio of 4.28 for NAION among patients prescribed semaglutide for type 2 diabetes, and 7.64 for those taking it for weight loss.8JAMA Network. Risk of Nonarteritic Anterior Ischemic Optic Neuropathy in Patients Prescribed Semaglutide A larger August 2025 study in JAMA Network Open, analyzing matched cohorts of nearly 160,000 patients, found a hazard ratio of 1.76 for NAION in patients taking semaglutide or tirzepatide (the active ingredient in Zepbound). The absolute risk remained low, with 35 NAION cases out of roughly 80,000 GLP-1 patients over two years.9JAMA Network. Semaglutide or Tirzepatide and Risk of Optic Nerve Disorders
A January 2025 case series in JAMA Ophthalmology examined nine patients who experienced severe vision loss on semaglutide or tirzepatide. Seven developed NAION. The authors proposed that rapid correction of high blood sugar by the drugs may trigger optic nerve swelling that progresses to NAION through a “compartment syndrome” mechanism in susceptible patients.10JAMA Network. Ophthalmic Complications Associated With the Antidiabetic Drugs Semaglutide and Tirzepatide
Other research has not found a significant link. A 2025 multinational study in Ophthalmology using propensity score matching on 18,657 patients with type 2 diabetes found no statistically significant increase in NAION risk with semaglutide.11Nature. GLP-1 Receptor Agonists and Risk of NAION A larger 2025 study in the American Journal of Ophthalmology similarly found no significant increase among GLP-1 users compared to matched controls with diabetes or high BMI.4American Journal of Ophthalmology. GLP-1 Receptor Agonists and Risk of NAION A May 2026 joint consensus statement from the North American Neuro-Ophthalmology Society and the American Academy of Ophthalmology concluded that while some studies suggest a small possible increased risk, the magnitude appears low and the evidence base is limited by the rarity of NAION.3American Academy of Ophthalmology. Glucagon-Like Peptide-1 Receptor Agonists and Risk of NAION
Where the Cases Stand
On December 15, 2025, the U.S. Judicial Panel on Multidistrict Litigation created MDL No. 3163, In re: Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RAs) Non-Arteritic Anterior Ischemic Optic Neuropathy Products Liability Litigation, and centralized it in the Eastern District of Pennsylvania before Judge Karen S. Marston.12U.S. Judicial Panel on Multidistrict Litigation. MDL-3163 Transfer Order The NAION MDL was deliberately kept separate from an existing, larger MDL (No. 3094) that handles gastrointestinal injury claims against the same GLP-1 manufacturers. Both are assigned to Judge Marston, but the injury types are on separate tracks. If your claim involves stomach paralysis, bowel obstruction, or other GI injuries rather than vision loss, it belongs in the other MDL, not this one.1MDL Update. MDL-3163 GLP-1 NAION Products Liability Litigation
As of June 2026, 110 cases are pending in the vision loss MDL.1MDL Update. MDL-3163 GLP-1 NAION Products Liability Litigation The proceeding is still in its early phase: a “Science Day” was scheduled for June 2, 2026, at which both sides would present non-adversarial scientific overviews to educate the judge on the medical background. Discovery and bellwether case selection are expected to follow. No settlements have been reached and no trial dates have been set.
Alongside the federal MDL, the New Jersey Supreme Court has approved the consolidation of Ozempic-related NAION vision loss lawsuits into a multicounty litigation in New Jersey state courts, where Novo Nordisk is headquartered.13Drugwatch. Ozempic Vision Loss Lawsuits to Be Consolidated in Novo Nordisks Home State
Eli Lilly’s Position and the Regulatory Split
Eli Lilly has denied the claims. In a medical information update reviewed as of March 2026, the company said that available clinical trial and postmarketing data “did not meet labelling criteria for clinical significance, causality to the drug, or relevance to patient safety and treatment decisions.” The company said it would update labeling in coordination with regulators if new information indicated a safety concern.14Eli Lilly. Is Zepbound Associated With Eye-Related Adverse Events
Lilly noted that independent publications may involve “varying scientific rigor and interpretations.” The current Zepbound label does say that rapid improvements in blood sugar control have been linked to temporary worsening of diabetic retinopathy and advises patients to contact a doctor about changes in vision, but it makes no specific mention of NAION.14Eli Lilly. Is Zepbound Associated With Eye-Related Adverse Events In February 2026, the FDA updated Zepbound’s label with recommendations for visually impaired patients and warnings for intestinal obstruction and severe constipation, but again did not add NAION language.15Robert King Law Firm. Zepbound Lawsuit
Regulators in the U.S. and Europe have diverged. In June 2025, the European Medicines Agency’s Pharmacovigilance Risk Assessment Committee concluded that NAION should be listed as a “very rare” side effect (affecting up to 1 in 10,000 people) on the labels for semaglutide products: Ozempic, Rybelsus, and Wegovy. The EMA review covered only semaglutide and did not extend to tirzepatide, the active ingredient in Zepbound and Mounjaro.16European Medicines Agency. PRAC Concludes Eye Condition NAION Is a Very Rare Side Effect of Semaglutide Medicines The FDA has not added a NAION warning to any GLP-1 label, though it is conducting a cohort study through its Sentinel surveillance system to assess the risk, with a protocol posted for public comment in June 2025. The agency emphasized that the existence of a Sentinel study does not necessarily indicate a confirmed safety problem.17FDA Sentinel Initiative. Risk of NAION Following GLP-1 Receptor Agonist Use Protocol
The gap between the EMA and FDA positions is likely to feature in the litigation. Plaintiffs can argue the European finding supports a known risk; defendants can point to the FDA’s continued silence as evidence that the science is unsettled. Lilly also has an epidemiological argument: at least one large study found no significant NAION increase in GLP-1 users compared to matched controls who had the same underlying diseases, suggesting the disease rather than the drug may be driving the injury.4American Journal of Ophthalmology. GLP-1 Receptor Agonists and Risk of NAION
Who May Have a Claim and Filing Deadlines
Potential plaintiffs are generally patients who took Zepbound, Mounjaro, or another GLP-1 receptor agonist and were subsequently diagnosed with NAION or a related optic nerve injury causing sudden, painless vision loss.
Filing deadlines vary by state. In most states, the statute of limitations for a product liability or personal injury claim runs two to three years from the date the injury was discovered or should have been discovered. Pennsylvania, where the MDL sits, generally allows three years. The discovery rule, which starts the clock when a plaintiff learns of the potential link between the drug and the injury, may extend the window for patients diagnosed before the research was widely publicized. Waiting for bellwether trial outcomes before filing risks missing state-specific deadlines.18Ethel Nostroff Law. Ozempic Blindness Lawsuit