Study Links Wegovy to 5x NAION Risk vs. Ozempic

A new study has found that patients using the weight loss drug Wegovy face nearly five times the risk of sudden vision loss compared to those taking Ozempic, both of which contain the active ingredient semaglutide. The research, led by Canadian scientists and published in the British Journal of Ophthalmology, analyzed adverse event reports submitted to the U.S. Food and Drug Administration from December 2017 to December 2024.

The investigation focused on nonarteritic anterior ischemic optic neuropathy, or NAION, a condition known as an eye stroke that results from restricted blood flow to the optic nerve, often causing permanent vision loss in one eye. Researchers reviewed more than 30 million reports overall, with 31,774 linked to semaglutide. Of those, over 20,000 involved Ozempic, approved in 2017 for type 2 diabetes at doses up to 2 milligrams weekly via injection, while about 3,000 concerned Wegovy, launched in 2021 for obesity treatment at higher doses of up to 2.4 milligrams weekly. Despite fewer total reports for Wegovy, its association with NAION was significantly stronger.

The study also identified a gender disparity, with men showing a threefold higher risk than...