A new study has found that the GLP-1 drug Wegovy is linked with a higher risk of “eye stroke,” especially in men. Ischemic optic neuropathy (ION) is a rare but serious condition that can cause sudden vision loss and even blindness. Researchers say semaglutide drugs like Wegovy may pose a greater risk of ION than Ozempic due to the higher doses used for weight loss. Doctors note the risk appears small but recommend steps to reduce it.
Researchers analyzed more than 30 million reports from the FDA’s public adverse-event database from late 2017 through 2024. That database collects voluntary reports from patients, clinicians, and manufacturers about side effects after taking medications. The team focused on reports where a GLP-1 receptor agonist was suspected in cases of ischemic optic neuropathy.
Semaglutide is available in multiple forms: Ozempic (weekly injection for type 2 diabetes), Wegovy (weekly, higher-dose injection for obesity), and Rybelsus (daily oral tablet for diabetes). The researchers examined each formulation separately, and also looked at tirzepatide, a newer dual-receptor agent, plus common diabetes drugs like metformin and insulin for comparison. They used statistical methods to detect whether a drug was reported with ION more often than expected by chance and adjusted analyses for age and sex.
Out of the tens of millions of reports, about 31,000 involved semaglutide. The obesity drug Wegovy showed the strongest link to ischemic optic neuropathy, even though it had fewer overall reports than Ozempic. Investigators suspect Wegovy’s higher dose — producing greater systemic exposure and faster weight loss — may influence blood flow to the optic nerve. The association was notably stronger in male patients. No ION cases were reported with the oral semaglutide (Rybelsus), which is absorbed more slowly in smaller amounts, suggesting delivery method and dose matter.
Tirzepatide did not show a significant association with vision problems despite producing large improvements in blood sugar and weight; researchers suggest its dual-receptor action may mitigate effects on optic nerve blood flow. Other common diabetes medications such as metformin and insulin also showed no increased risk, pointing toward a possible unique effect of higher-dose semaglutide rather than a general risk from improving glucose or losing weight.
Potential mechanisms proposed include reduced optic nerve perfusion from fluid loss, drops in blood pressure (particularly nocturnal hypotension), and vascular shifts associated with rapid weight loss. These changes could make the optic nerve more vulnerable to ischemic injury, though the exact biological pathway remains unconfirmed.
Because the FDA database relies on voluntary reporting, the data do not represent true incidence rates. Still, the pattern seen with Wegovy and the higher risk in men suggest clinicians should monitor patients, especially those prescribed higher doses for obesity. The study’s authors call for further research to better define who is most at risk and how to prevent this complication.
Experts not involved in the study emphasized context. Hector Perez, MD, a bariatric surgeon, said that untreated obesity, diabetes, and vascular disease threaten vision far more commonly than semaglutide appears to. Still, he advised practical precautions: avoid extremely rapid early weight loss by reducing calories gradually to prevent sudden drops in blood pressure or tissue perfusion; maintain good hydration, since appetite suppression can reduce fluid intake and worsen optic nerve perfusion; and be mindful of excessively low nocturnal blood pressure, a known risk factor for optic nerve ischemia.
Diala Alatassi, MD, an obesity medicine physician, recommended initiating therapy at lower doses and titrating slowly when patients have multiple health conditions. She urged patients to work with experienced weight-loss clinicians rather than self-titrating meds purchased online. Alatassi also advised staying current with eye care — especially diabetics — and getting baseline yearly eye exams before starting such medications. Both experts stressed following prescription instructions, noting that inappropriate use of these drugs can lead to adverse outcomes.
The study was published March 10 in the British Journal of Ophthalmology and highlights the need for clinicians and patients to be aware of potential, though rare, vision risks associated with high-dose semaglutide. Further controlled studies are needed to confirm causation, quantify actual risk, and identify strategies to mitigate danger while preserving the substantial benefits these drugs provide for weight loss and diabetes management.
