The US health regulator on Monday informed patients and healthcare providers of a potential increased risk of a serious eye condition associated with the use of GLP-1 drugs for weight loss and diabetes.
The US Food and Drug Administration said it is requiring GLP-1 drugs such as Eli Lilly’s Mounjaro and Zepbound, and Novo Nordisk’s Ozempic and Wegovy to add information to the “warnings and precautions” section of labeling about the potential increased risk of non-arteritic anterior ischemic optic neuropathy (NAION).
The condition is a common cause of sudden, painless vision loss, and may lead to permanent impairment of sight in some cases. It is caused by decreased blood flow to the front part of the optic nerve, but the underlying cause is not completely understood.
The FDA said it has evaluated clinical trial data, animal data, and post-marketing data, including observational studies and case reports.
Eli Lilly and Novo Nordisk did not immediately respond to Reuters’ requests for comment.
Last year, the European Medicines Agency’s safety committee said Wegovy and Ozempic may in very rare cases cause NAION, the first time a regulator had confirmed the side effect.
The condition may affect up to 1 in 10,000 people taking semaglutide, the active ingredient in Wegovy and Ozempic as well as in Novo’s other diabetes drug Rybelsus, for at least one year, EMA had said.
Four patients in Denmark, who experienced vision loss after using Novo’s GLP-1 drugs, were granted compensation, the Danish Patient Compensation had said last year.
A large study published in 2025 tracked nearly 175,000 diabetic patients treated with semaglutide and an equal number taking non-GLP-1 medications. It found that the risk of NAION more than doubled after two years of treatment with a GLP-1 drug, compared to diabetes medicines from other classes.



