Weight Loss and Vision Loss: Wegovy May Be Linked To Sudden Blindness

A large study has found a possible link between the use of the weight-loss drug Wegovy and a rare problem that can cause sudden vision loss. Although the risk is low, it appears to be higher than with similar medications, especially in men. More research is needed to confirm this relationship.

In recent years, obesity has become one of the biggest health challenges in the world. The number of overweight people has increased dramatically since the 1970s, bringing with it several health problems, such as heart disease, diabetes, and even reduced life expectancy.

In response, new medications have emerged to help with weight loss, offering a less invasive alternative to surgery. Among these medications, one of the best known today is Wegovy, which has been widely used.

These medications work in different ways in the body. Some reduce fat absorption, while others act on the brain and on hormones linked to hunger and satiety, helping the person feel less inclined to eat.

Wegovy belongs to this second group: it works by stimulating bodily mechanisms that increase the feeling of satiety. Therefore, it has become popular not only for medical treatment, but also as a lifestyle choice for those who want to lose weight.

However, with the increased use of these medications, concern about possible side effects is also growing. One of the most recent warnings involves a rare but serious problem related to vision.

This is a condition in which the nerve responsible for transmitting images from the eyes to the brain suffers an interruption in blood flow. When this happens, vision loss can occur rapidly and, in some cases, permanently.

To investigate this possible relationship, researchers analyzed a huge database in the United States that compiles reports of adverse drug effects. This system collects information submitted by healthcare professionals, patients, and manufacturers about problems that occur after the use of medications. In total, more than 30 million records were examined, including thousands of cases involving medications used for weight loss and diabetes.

Scientists compared different similar medications, including Wegovy and others with the same active ingredient, but used to treat diabetes. Despite having fewer total reports, Wegovy showed a much stronger association with cases of vision loss than the other medications analyzed.

In simple terms, this means that, proportionally, reports of this problem were much more frequent among Wegovy users.

More than 30 million reports of medication side effects were analyzed. Of these, approximately 31,774 cases involved medications with the same active ingredient as Wegovy.

Cases of vision problems (a rare condition) with Wegovy totaled 28 cases among 3,070 reports. This represents about 0.91% of cases. With Ozempic (a similar medication), there were 47 cases among 20,608 reports, approximately 0.23% of cases. The problem appeared about 4 times more frequently with Wegovy.

The risk was more than three times higher in men than in women. In terms of relative chance in the data: Men had the highest values ​​of association with vision problems. Women presented a lower risk, but still present.

Despite these findings, the researchers themselves emphasize that it is not yet possible to state with certainty that the medication directly causes vision loss. The type of study conducted shows associations, but does not prove cause and effect. Even so, the results raise an important alert, indicating the need for more studies to better understand this possible risk and guide doctors and patients in the safe use of these treatments.

READ MORE:

Effects of anti-obesity medications in the retina: a gathering storm or sunshine ahead?

Anna-Marie Muir, Helena Lee, Andrew J Lotery, and J Arjuna Ratnayaka

British Journal of Ophthalmology. 10 March 2026DOI: 10.1136/bjo-2025-329298

Abstract:

Ischaemic optic neuropathy (ION) is a rare but vision-threatening complication recently linked to GLP-1 receptor agonists, particularly semaglutide. Using over 30 million reports from the FDA Adverse Event Reporting System (2017–2024), we evaluated formulation- and sex-specific associations. Among 31 774 semaglutide cases, Wegovy demonstrated the strongest signal for ION (reporting odds ratio (ROR)=74.89) compared with Ozempic (ROR=18.81). Sex-stratified analyses showed higher odds in men (ROR=116.37), and multivariable regression confirmed greater risk with Wegovy versus Ozempic (adjusted OR (AOR)=4.74) and in men versus women (AOR=3.33). These findings highlight a potential dose-dependent safety concern that warrants urgent prospective evaluation to guide prescribing and regulatory policy.