US warns that Ozempic and other weight-loss drugs may cause vision loss and blindness

The US Food and Drug Administration (FDA) issued a new warning on Monday concerning Ozempic, Wegovy, Mounjaro and Zepbound, medications widely used to treat diabetes and obesity.

The warning follows the identification of a potentially increased risk of developing a serious eye condition that can cause sudden vision loss and, in some cases, permanent blindness.

The US regulatory agency has ordered manufacturers to include a specific warning in the prescribing information and safety documentation for these medications.

The condition associated with this risk is non-arteritic anterior ischemic optic neuropathy (NAION), a disorder that occurs when blood flow to the optic nerve, which transmits visual information from the eye to the brain, is reduced.

This interruption in blood supply can cause sudden, painless vision loss, usually affecting one eye, with potentially irreversible consequences.

Despite the potential severity of the condition, health authorities emphasize that it is a very rare complication and that the risk must be weighed against the proven clinical benefits of these treatments.

FDA identifies higher incidence among patients taking these medications

The FDA's decision follows a review of data from clinical trials, observational studies, animal research and reports of suspected adverse reactions.

An analysis of 126 clinical trials involving more than 134,000 participants identified an incidence of 6.4 cases of NAION per 100,000 person-years among patients treated with GLP-1 medications.

By comparison, participants receiving a placebo or other glucose-lowering medications experienced 3.8 cases per 100,000 person-years.

These findings suggest a possible increase in risk, although the absolute number of cases remains very low.

The agency also acknowledges that the biological mechanism behind this association has not yet been identified. Furthermore, several established risk factors for NAION, including diabetes and high blood pressure, are common among patients prescribed these medications.

Europe had already warned about the risk associated with Ozempic and Wegovy

The US warning follows earlier assessments by European health authorities concerning the same eye condition.

In June 2025, the European Medicines Agency (EMA) concluded that NAION is a very rare side effect of semaglutide, the active ingredient in Ozempic, Wegovy and Rybelsus.

According to the European regulator, the complication may affect up to one in every 10,000 people treated with semaglutide.

Epidemiological studies also found that adults with type 2 diabetes taking semaglutide could face approximately twice the risk of developing NAION compared with those not using the medication.

The United Kingdom updated its health warnings in February 2026.

The latest US decision extends the warning across the GLP-1 receptor agonist drug class, including products marketed by Novo Nordisk and Eli Lilly.

What are the warning signs?

Health authorities explain that NAION can develop suddenly and without pain, making its initial symptoms particularly difficult to anticipate.

The main warning signs include:

• Sudden vision loss in one eye, particularly upon waking up.

• Blurred vision or dark spots appearing in the visual field.

• Partial loss of peripheral vision or tunnel vision.

• Changes in color perception.

• Reduced sharpness of central vision.

The FDA advises patients to seek immediate medical attention if they experience any of these symptoms.

Suspected cases require an urgent ophthalmological assessment. Patients should not change or discontinue their prescribed treatment without consulting a healthcare professional.

Lawsuits filed by patients claiming to have lost their sight

The warning also coincides with a growing number of lawsuits against the manufacturers of these medications in the United States.

According to reports published by US media, dozens of lawsuits have been filed against Novo Nordisk since 2025 over alleged eye injuries linked to Ozempic and Wegovy.

Among the reported cases is Michelle Fennell, a 53-year-old woman who said she began experiencing vision problems approximately six months after starting Ozempic treatment for type 2 diabetes.

Another plaintiff, 69-year-old Jay Vandegriff, claims he suffered significant vision loss in his left eye after using the same medication.

These allegations are part of legal proceedings and do not, by themselves, establish that the medications caused the reported injuries.

Regulators emphasize that the risk remains very low

Despite the new warning, health regulators stress that NAION remains a rare condition and that GLP-1 medications offer demonstrated benefits in treating diabetes and obesity.

Factors that may increase the likelihood of developing this eye condition include diabetes, high blood pressure, smoking and sleep apnea, as well as certain kidney diseases.

The new safety warning does not mean that the medications are being withdrawn from the market. Instead, manufacturers are required to provide clearer information to healthcare professionals and patients about this potentially serious adverse effect.

The FDA considers continued monitoring of these increasingly widespread treatments essential and recommends paying particular attention to any sudden changes in vision.