Drugs based on semaglutide have become some of the most talked-about medicines in recent years. These drugs belong to a class called GLP-1 receptor agonists and are widely used to treat type 2 diabetes and obesity.
Some versions of the drug are also prescribed to reduce the risk of heart disease in people with diabetes. Because they can help people lose a significant amount of weight and improve blood sugar control, their popularity has grown rapidly around the world.
However, a new safety analysis suggests that one of these drugs may carry a higher risk of a rare but serious eye problem known as an “eye stroke.”
The study, published in the British Journal of Ophthalmology, found that Wegovy, a high-dose semaglutide medication used for weight loss, may have the strongest association with ischemic optic neuropathy, often shortened to ION.
Ischemic optic neuropathy happens when the blood flow to the optic nerve is reduced or blocked. The optic nerve carries visual information from the eye to the brain. If it does not receive enough blood and oxygen, the nerve can be damaged.
This damage can cause sudden vision loss in one eye or sometimes both eyes. Although this condition is rare, it can be very serious and may lead to permanent vision problems.
Researchers say that ION has recently been linked to GLP-1 receptor agonist drugs, especially semaglutide products such as Wegovy, Ozempic, and Rybelsus. These medications are used for slightly different purposes.
Ozempic is mainly prescribed to treat type 2 diabetes, while Wegovy is approved for weight loss at a higher dose. Rybelsus is a tablet form of semaglutide that is taken daily for diabetes.
To explore the possible connection between these drugs and eye stroke, the researchers analyzed reports submitted to the U.S. Food and Drug Administration’s Adverse Event Reporting System, commonly called FAERS.
This system collects reports of harmful or unexpected side effects from medications. The researchers reviewed reports submitted between December 2017 and December 2024.
The dataset was extremely large. Out of more than 30 million reports of harmful or unintended side effects linked to various medications, about 31,774 reports involved semaglutide drugs. The people described in these reports had an average age of 56 years, and just over half were women.
Among these reports, 3,070 were linked to Wegovy and 20,608 were linked to Ozempic. Ozempic generated many more reports mainly because it was approved earlier, in 2017, while Wegovy was launched later in 2021.
Despite this difference, the analysis showed that Wegovy had the strongest association with ischemic optic neuropathy. There were 28 reported cases of the eye condition linked to Wegovy, compared with 47 cases linked to Ozempic and 85 cases linked to generic semaglutide products.
When researchers calculated the relative strength of the association, they found that the signal for Wegovy was much stronger than for the other drugs. The odds of reporting ION were nearly five times higher with Wegovy than with Ozempic.
Another interesting finding was the difference between men and women. The risk signal for Wegovy was much stronger in men than in women. In men taking Wegovy, the reporting signal for ION was more than three times higher compared with women. For Ozempic, the strongest signal appeared in women rather than men.
The researchers also compared these drugs with other medications used for diabetes and obesity. These included tirzepatide, a newer drug that works on both GLP-1 and another hormone called GIP. Tirzepatide is sold as Mounjaro for diabetes and Zepbound for weight loss.
The analysis did not find the same strong signal linking those medications to ischemic optic neuropathy. In addition, the tablet form of semaglutide, Rybelsus, did not show any signal suggesting a connection to the eye condition.
The researchers believe that differences in how these drugs are taken may partly explain the findings. Injectable drugs enter the body faster than tablets. Wegovy is also prescribed at a higher dose than Ozempic. These factors may influence how the medication affects blood flow and blood pressure.
The scientists suggest that high-dose injectable semaglutide might contribute to reduced blood supply to the optic nerve in some patients. Possible mechanisms include changes in blood volume, drops in blood pressure during the night, and instability in the body’s automatic control of blood circulation.
In contrast, Rybelsus is absorbed more slowly through the digestive system. Its lower absorption rate may explain why no signal was detected in the analysis.
The researchers also caution that the FDA reporting system has important limitations. Because the database relies on voluntary reports, it cannot show how often a side effect actually occurs. It also does not include detailed medical information about the patients, such as other health conditions or how severe their illness was.
Media attention may also influence how often certain side effects are reported. If doctors or patients become aware of a possible risk, they may be more likely to report cases that occur afterward.
Despite these limitations, the researchers say their study provides the first evidence suggesting that the risk of ischemic optic neuropathy may depend on the specific formulation and dose of semaglutide. Wegovy, which uses the highest dose, showed the strongest association in the analysis.
Experts who wrote a commentary alongside the study say the findings add to a growing body of research suggesting that anti-obesity medications may sometimes be linked to eye complications. They say further research is urgently needed so doctors and eye specialists can better understand the risks.
The issue may become increasingly important as the use of these medications continues to grow. In the United Kingdom, for example, nearly 29 percent of adults are classified as obese, and about 64 percent of adults are either overweight or obese. Because of this, drugs like Wegovy are likely to be prescribed more often in the coming years.
In addition to helping with weight loss, some studies suggest these medications may also reduce the risk of cardiovascular diseases such as stroke and may even influence conditions like dementia. As a result, they are being considered as first-line treatments for some patients.
At the same time, their use is expanding into younger populations. Some doctors now prescribe these medications to adolescents over the age of 12 who have severe obesity. This growing use raises questions about long-term safety, including possible eye complications later in life.
Interestingly, some early research suggests that semaglutide drugs may also have potential benefits for certain eye diseases, such as age-related macular degeneration and uveitis. This makes the overall picture even more complex.
For now, researchers emphasize that ischemic optic neuropathy remains a rare condition. The study does not prove that these medications directly cause eye strokes. However, the findings highlight a possible safety concern that should be carefully studied in future clinical trials.
Doctors and patients are encouraged to remain aware of the potential risks while also considering the important benefits these medications can provide. With further research, scientists hope to better understand who may be most vulnerable and how these treatments can be used as safely as possible.
If you care about weight loss, please read studies about orange that could help obesity, and a berry that can prevent cancer, diabetes and obesity.
For more health information, please see recent studies about ginger’s journey in weight management, and green tea: a cup of weight loss.
Copyright © 2026 Knowridge Science Report. All rights reserved.
