Updated

The US Food and Drug Administration has ordered makers of Ozempic, Wegovy and other GLP-1 weight-loss drugs to add warnings about NAION, a rare eye condition that can cause blindness. BBC World reported on 10 November 2026 that the condition is known as non-arteritic anterior ischaemic optic neuropathy and happens when blood vessels supplying the optic nerves become blocked, depriving the nerves of oxygen. It can cause painless decreased vision in one eye, which can be permanent, and there is no known treatment to reverse it. Mounjaro and Zepbound are also covered by the warnings. The FDA said a detailed review found an increased risk of rare NAION events in people taking the drugs, though the reason is not known and some patients may have other risk factors. Novo Nordisk, the maker of Wegovy, said the data do not establish a cause-and-effect relationship. The American Academy of Ophthalmology said any added risk appears small and that patients should not stop their medication without talking to a doctor. The European Medicines Agency's safety arm said last year that up to 1 in 10,000 people taking semaglutide may be affected, and a study of 17,000 patients published two years ago found semaglutide users four times more likely to be diagnosed. Harvard professor Joseph Rizzo, a study author, called the findings "significant but tentative".