An accumulating number of lawsuits allege that popular GLP-1 weight-loss and diabetes medications like Ozempic and Wegovy may cause permanent vision loss, raising new questions over drug safety and warning disclosures in the US and Europe.
A growing body of litigation is putting renewed scrutiny on GLP-1 weight-loss and diabetes medicines after patients alleged that the drugs were linked to sudden, permanent vision loss. The cases centre on non-arteritic anterior ischaemic optic neuropathy, or NAION, a rare condition in which reduced blood flow damages the optic nerve and can leave people with lasting blind spots or complete loss of sight in one eye. According to reporting by Medical Daily and The Hearty Soul, the complaints stem from patients who say they lost vision after taking semaglutide-based medicines such as Ozempic and Wegovy, as well as other drugs in the class including Mounjaro and Trulicity.
NAION is especially difficult to untangle from the illnesses that often lead people to these medicines in the first place. Diabetes, high blood pressure, high cholesterol and sleep apnoea are all known risk factors for the condition, which means a patient who develops NAION while using a GLP-1 drug may already have been vulnerable. The condition typically appears without pain, often on waking, and no treatment has been shown to reliably restore lost vision, making early recognition crucial, according to the health reporting site Harm Report.
The legal pressure has now been gathered into federal multidistrict litigation in the US. Settlement Record reported that, as of September 2026, there were 216 active cases in MDL No. 3163, centralised in the US District Court for the Eastern District of Pennsylvania before Judge Karen Spencer Marston. Separate reporting by Drug Injury said the litigation was consolidated in December 2025 and that the claims cover Ozempic, Wegovy, Rybelsus, Mounjaro and Zepbound.
The scientific case remains unsettled, but regulators outside the US have already moved. Medical Daily said European authorities have accepted a very rare NAION risk tied to semaglutide, while Peptides Beat reported that the warning has been added to product information in the EU and UK but not in US labelling. That divergence has become a central issue in the lawsuits, where plaintiffs argue that manufacturers failed to warn patients soon enough, while the companies dispute causation and point to the limits of observational research.
For patients, the practical message is narrower than the courtroom fight: sudden, painless loss or dimming of vision needs urgent medical attention. The Hearty Soul and Harm Report both note that the risk appears small in absolute terms, but it is serious because NAION-related damage is generally permanent. The broader question for regulators and manufacturers is whether the evidence that emerged over the past two years should have prompted faster, clearer warnings in the US.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
