A new medical study suggests that Wegovy, one of the world’s most popular weight loss drugs, may be linked to a rare but potentially serious eye condition that can cause sudden vision loss.
The research, published in the British Journal of Ophthalmology, found that Wegovy showed the strongest association with ischemic optic neuropathy among several semaglutide-based medications examined.
The findings are important because prescriptions for GLP-1 drugs such as Wegovy and Ozempic have increased dramatically in recent years.
GLP-1 medications were originally developed to treat type 2 diabetes, but many are now widely used for obesity treatment because they can help people lose significant amounts of weight.
Wegovy and Ozempic both contain semaglutide as their active ingredient. Wegovy is approved specifically for obesity treatment, while Ozempic is mainly prescribed for diabetes. Another semaglutide drug called Rybelsus comes in tablet form.
The eye condition studied by researchers is called ischemic optic neuropathy, or ION.
ION happens when blood flow to the optic nerve becomes reduced or blocked. The optic nerve is responsible for carrying visual signals from the eye to the brain. Damage to this nerve can lead to sudden vision loss, which may sometimes become permanent.
Although the condition is considered uncommon, doctors take it very seriously because it can appear suddenly and may not always be reversible.
To study the possible connection, researchers analyzed reports submitted to the FDA Adverse Event Reporting System between 2017 and 2024.
This large database collects reports of side effects and medical problems linked to medications.
Scientists reviewed more than 30 million reports in total. Over 31,000 involved semaglutide drugs.
The researchers compared several medications, including Wegovy, Ozempic, Rybelsus, Mounjaro, and Zepbound.
Ozempic generated more reports overall because it was approved earlier and has been used longer. However, Wegovy produced the strongest statistical signal linked to ischemic optic neuropathy.
Researchers identified 28 reports involving Wegovy and 47 involving Ozempic.
Despite the lower number of Wegovy cases, the calculated odds linked to Wegovy were much higher. The statistical signal for Wegovy was nearly 75 times higher than expected, compared with around 19 times higher for Ozempic.
No cases of ischemic optic neuropathy were reported for Rybelsus, the oral semaglutide tablet.
Researchers also found differences between men and women.
Men taking Wegovy showed the strongest signal overall, with odds more than 100 times higher than expected. In women, the strongest association appeared with Ozempic.
Scientists believe several possible explanations may account for the stronger signal seen with Wegovy.
Wegovy is generally prescribed at higher doses than Ozempic. Injectable medications may also enter the body more rapidly than oral tablets.
Researchers suggested that rapid fluid loss, dehydration, blood pressure changes, or shifts in nervous system regulation could potentially reduce blood supply to the optic nerve in vulnerable individuals.
Still, the researchers emphasized that the study cannot prove Wegovy directly caused the eye condition.
The FDA reporting system has several important limitations. Many side effects are voluntarily reported, meaning some cases may be missing while others may receive more attention because of media coverage.
The database also does not include complete medical histories, making it difficult to separate the effects of the medication from other risk factors.
This is especially important because people with obesity and diabetes already face higher risks for blood vessel disease and eye complications.
Researchers stressed that the findings should be viewed as an early warning signal rather than final proof.
At the same time, experts say the results deserve serious attention because use of GLP-1 medications is expected to continue rising rapidly around the world.
Scientists are now studying these drugs for many additional uses beyond weight loss and diabetes treatment. Research suggests they may also help lower risks related to heart disease, kidney disease, stroke, sleep apnea, and dementia.
Because millions of people may eventually use these medications, even rare side effects could affect large numbers of patients overall.
Experts who commented on the study said ophthalmologists and researchers should investigate the issue urgently.
Interestingly, some evidence also suggests GLP-1 drugs may help protect against certain eye diseases, including inflammatory eye conditions and age-related macular degeneration.
This means the relationship between semaglutide drugs and eye health may involve both risks and potential benefits.
Carefully examining the study, the findings appear important but should be interpreted cautiously. The very large FDA database allowed researchers to identify rare patterns that smaller studies might miss, which strengthens the value of the research.
However, adverse event reporting systems cannot prove direct cause and effect and may be influenced by media attention, reporting bias, and missing information.
The strong signal associated with Wegovy clearly justifies further investigation, especially because the medication is prescribed at higher doses than some related drugs.
Future controlled studies will be necessary to determine whether the association reflects a true biological risk and which patients may be most susceptible. Until more evidence becomes available, experts recommend that patients using GLP-1 drugs remain aware of sudden vision changes and seek prompt medical care if symptoms occur.
If you care about eye health, please read studies about how vitamin B may help fight vision loss, and MIND diet may reduce risk of vision loss disease.
For more information about eye disease, please see recent studies about how to protect your eyes from glaucoma, and results showing this eye surgery may reduce dementia risk.
Source: British Journal of Ophthalmology.
