A new study has raised concerns about a possible link between the popular weight loss drug Wegovy and a rare eye condition that can cause sudden vision loss.
Researchers found that Wegovy showed a stronger association with ischemic optic neuropathy, also called ION, than other semaglutide medications studied. The findings were published in the British Journal of Ophthalmology.
Wegovy belongs to a group of medications called GLP-1 receptor agonists. These drugs have become extremely popular in recent years because they help people lose weight and improve blood sugar control. Some GLP-1 drugs are also used to treat type 2 diabetes.
Semaglutide is the active ingredient in Wegovy and Ozempic. Wegovy is approved for obesity treatment, while Ozempic is mainly approved for diabetes management. Another semaglutide drug called Rybelsus is available in tablet form.
The eye condition examined in the study, ischemic optic neuropathy, happens when blood flow to the optic nerve becomes blocked or reduced. The optic nerve carries visual information from the eye to the brain. Damage to this nerve can lead to sudden partial or complete vision loss, sometimes permanently.
Although ION is considered rare, researchers say it is a serious medical condition that deserves attention as use of GLP-1 drugs continues to grow worldwide.
To investigate the issue, scientists analyzed reports from the U.S. Food and Drug Administration Adverse Event Reporting System, also called FAERS. This database collects reports of side effects and harmful reactions linked to medications.
The researchers reviewed more than 30 million adverse event reports submitted between December 2017 and December 2024.
Among these reports, more than 31,000 involved semaglutide drugs. The average age of individuals in the reports was 56 years old, and slightly more than half were women.
The study examined several medications, including Wegovy, Ozempic, Rybelsus, and tirzepatide drugs such as Mounjaro and Zepbound.
Although Ozempic generated more reports overall because it has been on the market longer, Wegovy showed the strongest statistical signal linked to ischemic optic neuropathy.
Researchers identified 28 reports of ION associated with Wegovy and 47 associated with Ozempic. Despite the smaller number of Wegovy cases, the statistical odds linked to Wegovy were much higher.
According to the study, the signal for Wegovy was nearly 75 times higher than expected. For Ozempic, the odds were about 19 times higher. Generic semaglutide products showed odds around 21.
Interestingly, researchers found no reported cases of ION linked to Rybelsus, the oral semaglutide tablet.
The study also found differences between men and women. Men using Wegovy showed the highest statistical signal, with odds more than 100 times higher than expected. In women, Ozempic showed the strongest association.
Scientists believe several factors may explain why Wegovy showed a stronger signal.
One reason may involve dosage. Wegovy is generally prescribed at higher doses than Ozempic. Injectable medications may also act faster than oral drugs such as Rybelsus.
Researchers suggested that rapid weight loss, blood pressure changes, dehydration, fluid shifts, or changes in the autonomic nervous system might potentially reduce blood supply to the optic nerve in some individuals.
However, the researchers strongly emphasized that the study does not prove Wegovy directly causes the eye condition.
The FDA reporting database has important limitations. Reports are voluntary, and scientists cannot confirm whether the drug itself caused the problem. The database also does not provide full medical histories or detailed information about other risk factors patients may have had.
For example, obesity, diabetes, high blood pressure, and cardiovascular disease can themselves increase the risk of eye and blood vessel problems.
The researchers also noted that public attention surrounding Wegovy may have increased reporting of side effects, which could partly influence the results.
Still, the findings are drawing attention because GLP-1 medications are now being prescribed to millions of people worldwide.
Originally developed for diabetes treatment, these drugs are increasingly used for weight loss and are being studied for possible benefits involving heart disease, stroke prevention, kidney disease, sleep apnea, and even dementia.
Because their use continues to expand, researchers say it is important to carefully monitor rare side effects that may only become visible after very large numbers of people begin taking the medications.
Experts who wrote a related commentary said the findings deserve urgent attention from eye specialists and researchers.
At the same time, scientists noted that GLP-1 drugs may also have potential benefits for certain eye diseases, including age-related macular degeneration and uveitis.
This means the overall relationship between these medications and eye health may be more complicated than it first appears.
Reviewing the findings carefully, the study raises important safety questions but does not provide definitive proof of harm. The research relied on a large FDA reporting database, which is useful for detecting possible warning signals but cannot establish direct cause and effect.
The very strong statistical signal linked to Wegovy is concerning and clearly deserves further investigation. However, the total number of reported cases remained relatively small compared with the enormous number of people using these drugs worldwide.
More carefully controlled clinical studies will be needed to determine whether Wegovy truly increases the risk of ischemic optic neuropathy and to identify which patients may be most vulnerable.
Until then, experts say patients should not stop taking prescribed medications without speaking with their doctors, but should seek medical attention immediately if they experience sudden vision changes.
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.
