Popular GLP-1 medicines including Ozempic, Wegovy and Zepbound are facing a new legal challenge in the US, with dozens of patients alleging that the drugs caused sudden and potentially permanent vision loss. According to a report by The Wall Street Journal, patients have filed lawsuits against Novo Nordisk, maker of Ozempic and Wegovy, and Eli Lilly, which makes Zepbound, claiming they were not adequately warned about a possible risk of a rare eye condition called nonarteritic anterior ischemic optic neuropathy (NAION). The condition can cause sudden vision loss, typically affecting one eye.

The legal claims come as regulators and researchers continue to investigate a possible association between GLP-1 medicines and NAION. Importantly, the existence of lawsuits does not establish that the medicines caused the reported injuries. Evidence from studies remains mixed, and the manufacturers have disputed a causal connection.

The development is significant because GLP-1 receptor agonists have become widely used for type 2 diabetes and, in some cases, obesity and weight management. Medicines in this class include semaglutide, tirzepatide and other drugs that have transformed treatment for metabolic disease.

What are the lawsuits about?

The lawsuits allege that patients developed sudden vision loss after taking GLP-1 medicines and that drugmakers failed to provide adequate warnings about the potential risk.

The Wall Street Journal reported that dozens of patients have brought claims against Novo Nordisk and Eli Lilly, alleging that drugs including Ozempic, Wegovy and Zepbound were responsible for their vision problems. 

The allegations centre primarily on NAION. However, the lawsuits represent claims made by individual patients and do not, by themselves, demonstrate that the medicines caused their condition.

Novo Nordisk has rejected the allegations. According to reporting by ABC News, the company said it takes reports of adverse events seriously and considers the personal injury lawsuits to be without merit. 

Eli Lilly has likewise disputed claims linking its medicines to the eye condition, according to The Wall Street Journal.

Why has vision loss become a concern with GLP-1 drugs?

The concern initially emerged from observational research examining semaglutide, the active ingredient in Ozempic and Wegovy.

A 2024 multinational population-based study involving more than 297,000 people with type 2 diabetes, obesity or both found no statistically significant association between semaglutide and NAION across the groups studied. The researchers cautioned that the findings needed to be interpreted in the context of observational data.

Other studies, however, have reported a possible association, prompting continued investigation.

The World Health Organization issued a medical product alert in June 2025 after the European Medicines Agency recommended adding NAION to the product information for semaglutide medicines, including Ozempic, Rybelsus and Wegovy. The WHO described the reported frequency as very rare.

The UK's Medicines and Healthcare products Regulatory Agency subsequently stated that NAION had been reported very rarely in association with semaglutide and advised that patients experiencing sudden deterioration in vision should receive urgent ophthalmological assessment.

Also Read: Popular Weight Loss Drug Wegovy Linked To Rare Blinding Eye Condition, Finds Study

What does the latest research say?

The scientific evidence has not established a straightforward cause-and-effect relationship.

A 2026 systematic review and meta-analysis published in Ophthalmology examined six observational studies involving more than 4.8 million people. The pooled analyses did not demonstrate a statistically significant overall increase in NAION among semaglutide users compared with non-GLP-1 treatments. However, the researchers rated the certainty of the evidence as low to very low because of substantial differences between studies and other limitations. 

Another systematic review and meta-analysis published in Neurology in 2026 also noted that observational studies have produced conflicting findings regarding GLP-1 receptor agonists and NAION.

This distinction is important. A safety signal can prompt regulators to investigate or update prescribing information without proving that a drug directly causes the adverse event.

What are regulators saying?

The US Food and Drug Administration has been evaluating reports of NAION associated with several GLP-1 receptor agonists, including semaglutide, tirzepatide and other medicines in the class. FDA records indicate that the agency has been assessing whether regulatory action is necessary.

Meanwhile, regulatory authorities in Europe and the UK have moved to acknowledge the potential association with semaglutide as a very rare adverse effect.

This does not mean that everyone taking a GLP-1 medicine is at significant risk of losing vision. Rather, the current evidence suggests that a rare potential adverse event is being investigated, with the strength of the association still under scientific evaluation.

What should patients taking GLP-1 medicines do?

People prescribed GLP-1 medicines should not stop treatment on their own because of the lawsuits.

These drugs are used to treat important conditions, including type 2 diabetes and obesity, and treatment decisions need to consider their established benefits as well as potential risks.

However, sudden or rapidly worsening vision should never be ignored. UK regulators advise patients taking semaglutide to seek urgent ophthalmological assessment if they experience sudden loss or deterioration of vision. 

Patients concerned about their individual risk should discuss the issue with the doctor who prescribed the medicine, particularly if they have diabetes or other conditions that independently affect eye health.

The lawsuits against GLP-1 drugmakers add to growing scrutiny of the medicines as researchers investigate a possible link with rare sudden vision loss. While regulators in some countries have acknowledged a very rare association between semaglutide and NAION, studies have produced conflicting results and causation has not been conclusively established.

For now, the legal claims remain allegations, while the scientific question continues to be investigated. Patients taking GLP-1 medicines should not make treatment changes based solely on the lawsuits, but any sudden change in vision warrants immediate medical attention.



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