Are GLP-1s causing blindness? What we know about rare cases

Are GLP-1s causing blindness? What we know regarding rare cases.

Key points

• 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.
• 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.
• 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.
• The condition is more common in individuals over 50, according to the American Academy of Ophthalmology, and is rare.
• 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.

Are GLP-1s causing blindness? What we know regarding rare cases. Mary Walrath-Holdridge USA TODAY. Thousands sue over GLP-1 drugs: What patients allege.

Thousands of patients are suing over alleged GLP-1 drug injuries. Drugs include Ozempic, Wegovy and Mounjaro.

For context, a series of complaints filed within the last year focus on a specific condition called non-arteritic anterior ischemic optic neuropathy, or NAION. It causes rapid-onset vision changes and loss that can result in blindness. The rare disorder usually occurs in individuals over the age of 50 and its causes aren't entirely understood, but some GLP-1 users believe they have identified one source.

In practice, the drugmakers should have known and informed patients of the potential for this side effect, allege the lawsuits. It 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, nevertheless, have continued to roll in over the summer, creating another cluster of complaints. Here's what to know. Victims speak: Weight-loss drugs draw thousands of lawsuits alleging serious harm. 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 firms for serious complications including gastrointestinal injury and vision loss.

NAION has been the focus of plenty of of the most lately filed lawsuits. While another spate comes from Philadelphia, in New Jersey, almost 100 lawsuits related specifically to the eye condition have been filed since 2025.

By and sizeable, the lawsuits allege permanent vision loss and damage that occurred as of using the GLP-1 drugs Ozempic/Weogvy, Zepbound/Mounjaro and Trulicity (semaglutide, tirazepitde and dulaglutide). The complaining parties allege that Eli and Novo were or should have been aware of an rose risk of NAION. It they allegedly failed to communicate to patients.

"Defendants' efforts to conceal (or minimize) the risks associated with taking their 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 remarked.

USA TODAY previously documented 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 afterwards with loss of vision in one eye. He continued taking the medication, not knowing it had been linked to vision challenges 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 offer up his commercial driver's license. He can't see his grandkids play baseball, he remarked, and the couple has shelved much of their retirement travel bucket list, " USA TODAY noted.

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 employ, may additionally growth risk.

In practice, the condition is more common in individuals over 50, according to the American Academy of Ophthalmology, and is rare. Regarding two to 10 residents out of 100, 000 aged 50 or older obtain the disease yearly in the U.S.; that number decreases to less than 1 per 100, 000 residents in the general population, according to the AAO.

There is no treatment for NAION. Doctors identify and address any underlying problems that could be contributing to symptoms. Otherwise, patients are given supportive care and symptom management. Is NAION linked to GLP-1s?

There is at present 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 individuals published in JAMA Ophthalmology and a 2025 study published in the peer-reviewed journal Diabetes, Obesity and Metabolism. According to Both, they did and could not establish causation, even so.

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 backed by the American Academy of Ophthalmology. It stated in May that there was not ample evidence for such a blanket warning. The warning is additionally on labels for one or both major GLP-1s (semaglutide and tirazepitde) in the United Kingdom, the European Union, Denmark and Australia. Some labels and suits additionally 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, " AAO remarked 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 over 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 rose risk of vision loss, like diabetes. What do the firms say?

In court documents, the firms observed 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 remarked 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. Share your feedback to support improve our site!

In short, are GLP-1s causing blindness? What we know about rare cases is the central thread here, and readers can expect follow-up reporting as the picture becomes clearer.