Lawsuits are piling up against major GLP-1 makers Eli Lilly and Novo Nordisk as more patients accuse popular drugs like Ozempic and Zepbound of permanently damaging their eyesight.
A series of complaints filed within the last year focus on a specific condition called non-arteritic anterior ischemic optic neuropathy, or NAION, which causes rapid-onset vision changes and loss that can result in blindness. The rare disorder usually occurs in people over the age of 50, and its causes aren’t entirely understood, but some GLP-1 users believe they have found one source.
The drugmakers should have known and informed patients of the potential for this side effect, allege the lawsuits, which is not present on the warning labels for the medication in the U.S. It is included on updated labels in some other countries.
Some of the lawsuits have been consolidated, including a group of claims tied to alleged gastrointestinal injury. The NAION-related claims, however, have continued to roll in over the summer, creating another cluster of complaints.
What Do the Lawsuits Allege?
Thousands of lawsuits have been filed in state and federal courts, including at least 4,000 complaints that have been consolidated into larger federal and state litigation, against the drug companies for serious complications including gastrointestinal injury and vision loss.
NAION has been the focus of many of the most recently filed lawsuits. In New Jersey, nearly 100 lawsuits related specifically to the eye condition have been filed since 2025, while another spate comes from Philadelphia.
By and large, the lawsuits allege permanent vision loss and damage that occurred as a result of using the GLP-1 drugs Ozempic/Wegovy, Zepbound/Mounjaro and Trulicity (semaglutide, tirzepatide and dulaglutide). The complaining parties allege that Eli Lilly and Novo Nordisk were or should have been aware of an increased risk of NAION, which they allegedly failed to communicate to patients.
“Defendants’ efforts to conceal (or minimize) the risks associated with taking these drugs, including the risk of developing NAION, were intended to create the impression that these were ‘magic pills’ to help a person lose weight,” one July lawsuit filed against Eli Lilly in Pennsylvania state court said.
USA TODAY previously reported on one such case in which a 63-year-old man was prescribed Ozempic to manage his diabetes in 2023 and woke up four months later with loss of vision in one eye. He continued taking the medication, not knowing it had been linked to vision problems in some clinical trials and studies, and lost sight in his other eye in October 2024.
“Now legally blind, Engel has had to quit his job and give up his commercial driver’s license. He can’t see his grandkids play baseball, he said, and the couple has shelved much of their retirement travel bucket list,” USA TODAY reported.
What Is NAION?
Non-arteritic anterior ischemic optic neuropathy, or NAION, is a condition that causes sudden vision loss in one or sometimes both eyes. Sometimes referred to as an “eye stroke,” it is caused by a lack of blood flow to the optic nerve, according to the Cleveland Clinic.
Doctors don’t know exactly why it happens, but some health conditions may contribute to disruption of the eye’s blood flow, including diabetes, high or low blood pressure, anemia, sleep apnea and migraines. Some lifestyle factors, like smoking or medication use, may also increase risk.
The condition is more common in people over 50, according to the American Academy of Ophthalmology, and is rare. About two to 10 people out of 100,000 aged 50 or older get the disease yearly in the U.S.; that number decreases to less than 1 per 100,000 people in the general population, according to the AAO.
There is no treatment for NAION. Doctors identify and address any underlying issues that could be contributing to symptoms. Otherwise, patients are given supportive care and symptom management.
Is NAION Linked to GLP-1s?
There is currently not enough research to definitively establish a cause-and-effect relationship between GLP-1s and NAION or other vision changes.
Evidence linking the two has been mixed. Some research has suggested an association specifically between the condition and semaglutide, the active drug in Ozempic, such as a 2024 study of almost 17,000 people published in JAMA Ophthalmology and a 2025 study published in the peer-reviewed journal Diabetes, Obesity and Metabolism. Both noted that they did not and could not establish causation, however.
Other studies show no association or correlation, including a Novo-funded study from April and two 2025 studies published in the American Journal of Ophthalmology and the journal Ophthalmology.
In June, Novo Nordisk updated its European labels for Wegovy and Ozempic to state that semaglutide may cause NAION in up to 1 in 10,000 patients. This was not placed on updated labels in the U.S., a move supported by the American Academy of Ophthalmology, which said in May that there was not ample evidence for such a blanket warning. The warning is also on labels for one or both major GLP-1s (semaglutide and tirzepatide) in the United Kingdom, the European Union, Denmark and Australia. Some labels and lawsuits also reference dulaglutide, the active ingredient in Trulicity, another GLP-1 medication sold by Eli Lilly.
“A review of the available data has not established that semaglutide causes NAION, only a potential link between the two,” the AAO said in a press release. “…overall magnitude of the risk of NAION remains low. Shared decision-making between each patient and their care team is warranted to decide whether to start, continue or discontinue GLP-1 RAs.”
Labels for Ozempic have been updated in the U.S. multiple times in recent years to add side effects like intestinal obstruction, but nothing vision-related.
Researching the potential link between the two is complicated by the types of studies done, how the condition is defined and coded in medical documents, and how often it is associated with other diseases that carry an increased risk of vision loss, like diabetes.
What Do the Companies Say?
Both Novo Nordisk and Eli Lilly have denied any significant relationship between their GLP-1s and NAION and are engaged in litigation to defend the safety of the drugs.
In court documents, the companies noted that diabetic patients are already at a higher risk of blindness and other conditions that have been the subject of GLP-1-related lawsuits, like gastroparesis and intestinal dysfunction.
“The safety profile of GLP-1 RAs has been well-established in hundreds of clinical trials, large-scale observational studies and nearly two decades of real-world use,” the drugmakers said in a joint 2024 filing. “The known risks associated with these medicines are reflected in their FDA-approved product labeling, which, collectively, FDA has reviewed more than 40 times, and are discussed in textbooks, treatment guidelines and journals.”
USA TODAY reached out to Novo Nordisk and Eli Lilly for comment.
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