FDA requires label warning for GLP-1 drugs over rare eye condition risk

The Food and Drug Administration announced that manufacturers of GLP-1 receptor agonist medications, including semaglutide-based products such as Ozempic, Wegovy, Zepbound and tirzepatide-based Mounjaro, must add a label warning about a potential increased risk of non-arteritic anterior ischemic optic neuropathy (NAION). NAION is a rare condition that can cause sudden, often permanent vision loss due to restricted blood flow to the optic nerve.

The agency’s safety communication noted that NAION occurs in roughly two to ten people per 100,000 in the general population, and many risk factors for the condition—such as diabetes, hypertension, high cholesterol, metabolic syndrome and obstructive sleep apnea—are common among patients who use GLP-1 drugs. The FDA’s own meta-analysis of 126 trials involving more than 130,000 participants identified 15 probable NAION cases, ten of which occurred in patients receiving a GLP-1 drug.

Earlier research has produced mixed findings. A 2024 Harvard study reported higher NAION rates among patients on semaglutide compared with those on non-GLP-1 therapies, but the study was limited to a single referral center and may not be generalizable. Subsequent meta-analyses and observational studies have alternately found no association or a limited association only under specific comparative conditions.

The FDA’s labeling requirement aligns with a 2025 European Medicines Agency review that classified NAION as a very rare side effect of semaglutide, affecting up to one in 10,000 users. Both agencies advise clinicians to consider discontinuing a GLP-1 drug if a patient develops NAION, unless the therapeutic benefits clearly outweigh the risk.

The American Academy of Ophthalmology, which issued a joint consensus statement with the North American Neuro-Ophthalmology Society, emphasized shared decision-making for patients who develop NAION or who have elevated risk factors. In an emailed comment, the academy said the FDA’s warning is broadly consistent with its own conclusions, noting that while an association may exist, causation has not been established and the absolute risk increase appears small.