In March 2025, the Food and Drug Administration added a rare, sudden form of vision loss to its list of potential serious risks for GLP-1 drugs and said it was "evaluating the need for regulatory action." Eighteen months later, the current U.S. prescribing information for Ozempic, Wegovy, Rybelsus, and Mounjaro still does not mention the condition, even as regulators in Europe, the United Kingdom, and Australia have issued warnings.
The condition is non-arteritic anterior ischemic optic neuropathy, or NAION, a loss of blood flow to the optic nerve that can permanently damage sight. For the millions of Americans taking these drugs, the gap raises a practical question about what patients are told and when.
A label warning shapes what prescribers discuss before starting a drug, what information pharmacists hand out, and whether a patient links a sudden change in vision to a medication. Without it, U.S. patients may learn about the possible risk from news coverage or lawsuits rather than from their doctor.
FDA's Own Signal and an Unfinished Review
The FDA's quarterly list of potential safety signals, covering October to December 2024, names GLP-1 receptor agonists, including Ozempic, Wegovy, Rybelsus, Mounjaro, and Zepbound, alongside NAION. Appearing on the list does not mean the FDA has concluded that a drug causes a problem.
The agency is also studying the question through its Sentinel system. A Sentinel analysis of NAION risk with GLP-1 drugs, posted in June 2025 and using insurance claims and health record data from 2018 through mid-2024, is still listed as in progress, with no results released.
Asked about the issue this month, an FDA spokesperson told ABC News that the agency "routinely monitors the safety of drug products postmarketing" and "takes regulatory actions when appropriate." The FDA has not said when its review will finish.
Regulators Abroad Have Moved Further
The European Medicines Agency concluded in June 2025 that NAION is a very rare side effect of semaglutide, meaning it "may affect up to 1 in 10,000 people." The agency advised that patients with sudden vision loss or rapidly worsening eyesight "should contact their doctor without delay" and that semaglutide should be stopped if NAION is confirmed.
The United Kingdom's Medicines and Healthcare products Regulatory Agency followed with a February 2026 safety update on semaglutide telling clinicians to urgently refer patients with sudden vision loss to an ophthalmologist. Australia's Therapeutic Goods Administration went broader in July 2026, adding class-wide NAION warnings for GLP-1 drugs that also cover Mounjaro, Trulicity, and Saxenda.
Current U.S. labels do warn about diabetic retinopathy complications, a separate eye problem linked to rapid improvement in blood sugar control. That warning is not the same as a NAION warning.
MedicalDaily has reported on the lawsuits and the low absolute risk behind NAION claims. As of Sept. 1, 216 cases were consolidated in federal court in Philadelphia, where U.S. District Judge Karen S. Marston has ordered that general causation and federal preemption of failure-to-warn claims be addressed first.
The Evidence Gap Regulators Are Weighing
Studies point in the same direction but differ sharply on the size of the risk. A 2024 Mass Eye and Ear study found much higher NAION rates among semaglutide users. A 2025 analysis of 37.1 million people with type 2 diabetes found "a modest increase in the risk of NAION" that was "smaller than that previously reported." A study of 588,168 U.S. veterans with type 2 diabetes, published in April 2026, found 39.07 cases per 10,000 GLP-1 users over three years, compared with 29.33 per 10,000 among people taking SGLT2 inhibitors, another class of diabetes drugs.
None of these observational studies proves that the drugs cause NAION. Conditions such as diabetes, high blood pressure, and sleep apnea also raise NAION risk, which makes cause and effect hard to separate. That is one reason regulators have reached different conclusions from similar data: Europe's decision focused on semaglutide, while Australia chose to warn across the whole drug class.
Dr. Joseph Rizzo, a Mass Eye and Ear neuro-ophthalmologist and senior author of the 2024 study, told the Boston Globe, "I would not take my findings and use them to recommend that patients stop taking their medications." Novo Nordisk said it "believes the personal injury lawsuits filed in the U.S. are without merit and are vigorously defending them," and Eli Lilly said, "patient safety is Lilly's top priority."
Practical Steps for Patients Taking GLP-1 Drugs
The main warning sign is sudden, usually painless vision loss or blurring in one eye, often noticed on waking. Anyone taking a GLP-1 drug who experiences this should seek urgent medical care. A prompt exam also helps rule out other causes, such as stroke or retinal problems.
Patients should not stop a prescribed GLP-1 drug on their own because of this news. For many people, these drugs lower blood sugar, body weight, and heart risk, and stopping can undo those benefits. People with prior optic nerve problems, diabetic eye disease, or other risk factors can ask their prescriber and eye doctor whether extra monitoring makes sense.
The next milestones are the FDA's Sentinel results, any label decision, and a court briefing on causation scheduled for 2027. MedicalDaily will report whether the FDA's review leads to a label change.
Key Questions Answered
What is NAION? A loss of blood flow to the optic nerve that can cause sudden, often painless, and sometimes permanent vision loss in one eye.
Do U.S. GLP-1 labels warn about NAION? No. As of September 2026, current U.S. labels for Ozempic, Wegovy, Rybelsus, and Mounjaro warn about diabetic retinopathy complications but not NAION.
What did the FDA do in 2025? It listed NAION as a potential safety signal for GLP-1 drugs and said it was evaluating the need for regulatory action. Its Sentinel study is still in progress.
How rare is it? The European Medicines Agency estimates it may affect up to 1 in 10,000 semaglutide users.
Should I stop my GLP-1 medication? Not without talking to your prescriber. Seek urgent care for any sudden vision loss.
Published by Medicaldaily.com
