The US Food and Drug Administration (FDA) is requiring every GLP-1 drug, including Ozempic, Wegovy, Mounjaro and Zepbound, to carry a new warning about NAION, a rare eye condition that can cause sudden, permanent vision loss in one eye. In a Drug Safety Communication issued on November 9, 2026, the agency said it found "a potential increased risk of rare NAION events" but did not conclude that the drugs cause it. Patients should not stop their medication without talking to a doctor.
FDA GLP-1 eye warning, the key facts:
- What changed: NAION is being added to the Warnings and Precautions section of all GLP-1 drug labels.
- Drugs covered: semaglutide (Ozempic, Wegovy, Rybelsus), tirzepatide (Mounjaro, Zepbound), liraglutide (Victoza, Saxenda), dulaglutide (Trulicity) and others in the class.
- The risk: about 6.4 NAION cases per 100,000 patient-years on GLP-1 drugs, versus 3.8 on comparison treatments, in an FDA review of 126 trials.
- Symptoms: sudden, painless vision loss or blurring in one eye.
- What to do: keep taking your medicine unless your doctor says otherwise, and seek care promptly if symptoms appear.
What Is NAION?
Nonarteritic anterior ischemic optic neuropathy (NAION) happens when blood flow to the optic nerve, which carries signals from the eye to the brain, is reduced. The FDA describes it as a rare condition that can cause sudden, painless, decreased vision in one eye, which can be permanent. The American Academy of Ophthalmology told the BBC there is no known treatment to reverse the vision loss, and that NAION is the most common cause of acute optic nerve injury in people over 50.
According to the FDA, NAION occurs in 2.3 to 10.2 people per 100,000 adults over 50 each year in the general population.
What the FDA Found
The agency's Drug Safety Communication is based on several lines of evidence:
- A meta-analysis of 126 clinical trials: NAION occurred at 6.4 events per 100,000 person-years among GLP-1 users versus 3.8 among patients on placebo or other glucose-lowering drugs. Only 15 probable NAION events were identified.
- Real-world data from the FDA's Sentinel system in adults with type 2 diabetes: GLP-1 users had a higher risk than users of DPP-4 inhibitors (hazard ratio 1.43), but the comparison with SGLT-2 inhibitors was not statistically significant.
- Reports and published studies, which the FDA said were hard to interpret because many GLP-1 patients already have NAION risk factors such as diabetes.
The FDA said the cause of NAION is not fully understood and that animal studies did not reveal how GLP-1 drugs might trigger it. That is why the label speaks of a "potential" risk.
Which GLP-1 Drugs Get the New Warning?
| Active ingredient | Brand names |
|---|---|
| Semaglutide | Ozempic, Wegovy, Rybelsus |
| Tirzepatide | Mounjaro, Zepbound |
| Liraglutide | Victoza, Saxenda |
| Dulaglutide | Trulicity |
| Orforglipron | Foundayo |
| Combinations and others | Xultophy, Soliqua, generic exenatide |
The list follows the FDA's communication as reported by Pharmacy Times.
What Drugmakers and Doctors Say
Novo Nordisk, which makes Ozempic and Wegovy, told the BBC it believes the data "do not establish a cause-and-effect relationship", adding that patient safety "is a top priority". The American Academy of Ophthalmology said "any added risk appears small, and it has not been established that these medications cause NAION", and urged patients: "Don't stop your medication without talking to your doctor."
Regulators elsewhere moved earlier. In 2025, the European Medicines Agency's safety committee concluded that NAION is a very rare side effect of semaglutide, estimating it may affect up to 1 in 10,000 people taking it. A US study of about 17,000 patients published two years ago found semaglutide users were four times more likely to be diagnosed with NAION, though one of its authors, Harvard ophthalmologist Dr Joseph Rizzo, called the findings "significant but tentative".
What Patients Should Do
- Do not stop treatment on your own. GLP-1 drugs treat diabetes, obesity and heart risk, and stopping suddenly has its own risks.
- Know the warning signs: sudden, painless vision loss in one eye, a blurred or missing area of vision, colour distortion, or reduced sharpness.
- Act quickly. The FDA says to contact a health care professional right away, and doctors are told to refer suspected cases promptly to an ophthalmologist.
- If you have had NAION before, talk to your doctor about whether to continue, as the risk of recurrence is higher.
- Report side effects to the FDA's MedWatch program online or at 1-800-332-1088.
Why It Matters for the GLP-1 Market
GLP-1 drugs are among the world's best-selling medicines, and a class-wide label change touches every company in the market, from Novo Nordisk and Eli Lilly to makers of newer oral drugs. Label warnings rarely stop prescribing on their own, but they shape how doctors screen patients and what insurers and employers weigh when deciding coverage. Expect the warning to feature in prescribing discussions for patients with existing eye disease or a past NAION diagnosis.
For more health coverage, see our guide to the benefits and risks of running every day.
FAQs
Does Ozempic cause blindness?
The FDA found a potential increased risk of NAION, a rare condition that can cause vision loss in one eye. It did not conclude that GLP-1 drugs cause it, and the absolute risk is small.
Should I stop taking Wegovy or Mounjaro?
No, not without speaking to your doctor. Seek urgent care if you notice sudden vision changes.
How common is NAION on GLP-1 drugs?
In the FDA's trial analysis, about 6.4 cases per 100,000 patient-years, compared with 3.8 on other treatments.
This article is for information only and is not medical advice. Checked on November 11, 2026, against the FDA's Drug Safety Communication, BBC News and Pharmacy Times.