Patients taking GLP-1 drugs for at least one year: about 6 per 100,000
The U.S. Food and Drug Administration announced Nov. 9 that it will add a warning about a possible rare side effect to the labeling of all GLP-1 drugs. Ozempic and Wegovy, two popular weight-loss drugs, are among the medicines covered by the class-wide action.
The GLP-1 class includes a dozen injectable or pill-based drugs used to treat obesity, diabetes and several other medical conditions. In addition to Ozempic and Wegovy, the FDA said the labeling change includes widely used brands such as Zepbound and Mounjaro.
The warning concerns non-arteritic anterior ischemic optic neuropathy, an eye condition that can cause significant vision loss, including permanent loss in some cases. The FDA said the problem had been reported with all GLP-1 drugs and described it as a possible rare side effect.
An FDA analysis of more than 125 clinical trials found the condition in roughly 6 of every 100,000 patients who took a GLP-1 drug for at least one year. The comparable rate among people taking a placebo or other types of glucose-lowering medications was less than 4 per 100,000, the FDA said.
The FDA also found reports of the condition in its electronic reporting system for drug injuries and side effects. FDA scientists began looking into the issue after the publication of a 2024 medical paper tying the condition to certain patients taking semaglutide, the active drug in Eli Lilly’s Ozempic.
The FDA said decreased blood flow to the optic nerve causes non-arteritic anterior ischemic optic neuropathy, although the underlying cause is not understood.
Symptoms include blurred vision, blind spots, distorted colors and other visual disturbances, according to the FDA. The agency said patients experiencing those symptoms should contact a health care professional immediately.