Hundreds of lawsuits accuse Novo Nordisk and Eli Lilly of selling GLP-1 drugs that caused a sudden and often permanent form of vision loss. The suits name semaglutide, tirzepatide, and dulaglutide, sold under brand names including Ozempic, Wegovy, Zepbound, Mounjaro, and Trulicity, AZFamily and Gray News reported. The claims center on an eye condition called non-arteritic anterior ischemic optic neuropathy, or NAION.
The allegations have not been proven in court, and both drugmakers dispute them. For the millions of Americans taking these drugs for diabetes or weight loss, the lawsuits raise a practical question: How worried should they be?
Current evidence suggests a real but small added risk with semaglutide. European regulators concluded in June 2025 that NAION is a very rare side effect of semaglutide, affecting up to 1 in 10,000 people who take it. Diabetes itself is a known risk factor for the condition, which makes it harder to separate a drug's role from the disease it treats.
Legal Claims and the Companies' Responses
According to AZFamily, which cited USA Today, thousands of lawsuits have been filed against the two companies over GLP-1 complications, including gastrointestinal injuries, and hundreds specifically allege NAION. The suits argue that the drugmakers should have warned patients about the risk. NAION does not appear on U.S. warning labels for these drugs, though it has been added to some labels in other countries.
In one case, a 63-year-old man prescribed Ozempic for diabetes in 2023 woke up about four months later with vision loss in one eye. Not knowing the cause, he kept taking the drug and lost sight in the other eye in 2024. He is now legally blind, according to USA Today.
Interest in the litigation is growing. Maria Raciti, a personal injury attorney at Phillips Law Group in Phoenix, said her firm represents 18 clients alleging GLP-1 injuries of all types. "We have gotten around close to 200 calls," she said.
In statements to NBC News, Novo Nordisk said it is fighting the lawsuits vigorously, and Eli Lilly said patient safety is its top priority. Novo Nordisk has also called the lawsuits meritless and pointed to company-funded research that found no increased risk, Fox News reported.
The Evidence Shows an Association, Not Proof
NAION occurs when blood flow to the front of the optic nerve drops, causing sudden, usually painless vision loss, most often in one eye. There is no proven treatment to restore lost vision.
Concern grew after a 2024 observational study by researchers at Mass Eye and Ear, part of Mass General Brigham, found higher NAION rates among semaglutide users. Observational studies can show a link but cannot prove that a drug caused a condition, and some later studies did not find an increased risk.
The strongest regulatory finding came from the European Medicines Agency's safety committee. It concluded that several large studies suggest semaglutide roughly doubles NAION risk in adults with type 2 diabetes, which equals about one additional case per 10,000 person-years of treatment. The agency advised patients with sudden vision loss or rapidly worsening eyesight to contact a doctor right away and said semaglutide should be stopped if NAION is confirmed. The World Health Organization issued an alert echoing that finding.
Newer U.S. data point the same way on a small scale. A study of 588,168 veterans with type 2 diabetes, published in JAMA Network Open, found 39.07 NAION cases per 10,000 people over three years among those who started a GLP-1 drug, compared with 29.33 among those who started an SGLT2 inhibitor, another diabetes drug class. That works out to about one extra case per 1,000 patients over three years. The study population was more than 90% male, so the results may not apply equally to everyone.
The FDA has not added a NAION warning to U.S. labels for these drugs. Most research has focused on semaglutide, so evidence for the other GLP-1 drugs named in the lawsuits is more limited.
Patients with Diabetes Face a Tangled Risk Picture
NAION is uncommon to begin with, occurring in roughly 2 to 10 of every 100,000 people over 50 each year. Known risk factors include diabetes and high blood pressure, conditions that are common among people prescribed GLP-1 drugs.
That overlap matters most for older adults with type 2 diabetes, who carry the clearest risk in current studies, and for anyone who has already had NAION in one eye. For families, the concern extends beyond vision to independence, including driving, working, and caring for others.
Stopping a GLP-1 drug abruptly carries its own risks, including higher blood sugar and weight regain. Patients should not stop or change a prescription without talking with the clinician who prescribed it. Those worried about their eyes can ask whether a baseline eye exam makes sense and whether another diabetes or weight-loss medicine would fit their situation.
The key warning sign is sudden, painless loss or dimming of vision in one eye, often noticed on waking and sometimes affecting the upper or lower half of the visual field. That requires same-day evaluation by an eye doctor or emergency department. Sudden vision loss with weakness, facial drooping or trouble speaking may signal a stroke and warrants a 911 call.
The lawsuits will move slowly. MedicalDaily will follow any U.S. label change, new studies, and major court rulings.
The lawsuits are allegations, not findings, but research does suggest a small added risk of NAION with semaglutide. Most patients are unlikely to be affected, and the most important step is knowing the warning signs and acting quickly if vision changes suddenly.
Key Questions Answered
What are the GLP-1 vision loss lawsuits about?
Hundreds of patients allege that drugs such as Ozempic, Wegovy and Mounjaro caused NAION, a form of sudden vision loss, and that the companies failed to warn them. The claims have not been proven.
How common is NAION in people taking semaglutide?
European regulators say it may affect up to 1 in 10,000 people taking semaglutide and classify it as a very rare side effect.
Does the research prove GLP-1 drugs cause vision loss?
No. Studies show an association, and European regulators list NAION as a very rare side effect of semaglutide, but the FDA has not added a NAION warning to U.S. labels.
Should I stop taking Ozempic or a similar drug?
Do not stop or change a prescription without speaking to your prescriber. Stopping suddenly can raise blood sugar and cause other problems.
What symptoms need urgent care?
Sudden, painless vision loss or dimming in one eye, often noticed on waking, needs same-day evaluation. Vision loss with weakness or trouble speaking needs a 911 call.
Published by Medicaldaily.com
