Dozens of people sue GLP-1 drug companies over alleged vision loss

Diabetes and weight-loss medications are believed by some to be the cause of their mysterious loss of vision.

Dozens of people have filed lawsuits in the United States against GLP-1 companies, which make popular weight-loss drugs like Ozempic and Mounjaro, claiming their products caused a rare condition that can cause permanent vision loss, US media outlets report.

The cases and alleged risk could present a significant challenge to a fledgling industry that analysts expected to generate about $100bn in annual sales in the next 10 years after being taken by millions of people in the US and making inroads into combatting widespread obesity in the country.

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A spokesperson for Novo Nordisk, the pharmaceutical giant that makes Wegovy and Ozempic, said the lawsuits lacked merit and the company was vigorously contesting them, according to The Wall Street Journal, while Eli Lilly, which produces Zepbound, did not comment on the litigation but said it was reviewing the data on potential health risks.

The lawsuits asserted that the drugs cause nonarteritic anterior ischemic optic neuropathy, or NAION, an eye condition that prevents adequate blood flow and damages the optic nerve, potentially resulting in permanent vision loss.

In one lawsuit filed by a woman in Pennsylvania described to The Washington Post, the patient said that after taking medication for her diabetes, her vision was like looking through a “fishbowl”. Two weeks later, she was diagnosed with NAION.

Scientists have been researching the possible connection between the condition and weight-loss drugs for years, but their findings remained mixed.

What is NAION?

NAION is a condition in which sudden loss of vision happens due to a painless reduction of blood flow to the optic nerve. It is often also referred to as an “eye stroke”.

The damage is usually irreversible and quite rare.

Scientific research has pointed to possible incidents in which patients who have taken GLP-1s end up being more likely to develop the condition.

It remains unclear how or if the drug is the cause of these problems.

Researchers have said, however, that for those who do develop the condition, it happens within the first six to 18 months of starting a GLP-1 medication.

What lawsuits have been filed?

A personal-injury firm in the US called Weitz & Luxembourg has filed more than 90 lawsuits against Novo Nordisk in a New Jersey state court since 2025 on behalf of patients who have developed NAION while taking their products.

Separate lawsuits have also been filed in the US District Court for the Eastern District of Pennsylvania, claiming that GLP-1 treatments caused NAION and drugmakers failed to adequately warn of their risks.

A Novo Nordisk company-funded study conducted randomised trials on GLP-1 patients and said they found the drugs do not cause any increase in the risk of NAION.

Dr Tina Vilsboll, a senior medical officer at Novo Nordisk and the lead author of the study, said she sees “no causality” and there are no “indications that we should really be worried about NAION”.

The European Medicines Agency said the eye condition could impact one of every 10,000 GLP-1 users who have diabetes.

The North American Neuro-Ophthalmology Society and the American Academy of Ophthalmology said that despite the reports that there is a small possible increase in risk, there are also studies that report no correlation and “the overall magnitude of the risk of NAION remains low.”

Despite the lawsuits, the US has not added any warnings on GLP-1 medications.

The US Food and Drug Administration has been investigating the link after early reports on the connection in 2024.