The agency’s review of 126 clinical trials found 6.4 cases per 100,000 patient-years among people taking the drugs, compared with 3.8 among those on comparison treatments, and it is telling patients to seek care right away for sudden, painless vision loss.
The Food and Drug Administration on Monday ordered the makers of every GLP-1 drug sold in the United States, including Novo Nordisk’s Ozempic and Wegovy and Eli Lilly’s Mounjaro and Zepbound, to add a warning about a rare eye condition that can cause permanent vision loss.
In a Drug Safety Communication dated Nov. 9, the agency said it had concluded there is “a potential increased risk of rare NAION events in patients taking GLP-1 RAs” and is requiring the information in the Warnings and Precautions section of each drug’s label. NAION, or non-arteritic anterior ischemic optic neuropathy, occurs when blood flow to the front of the optic nerve drops. It typically causes sudden, painless loss of vision in one eye, often noticed on waking.
The order covers every approved GLP-1 drug, from older diabetes treatments such as Victoza and Trulicity to Foundayo (orforglipron), a pill approved this year.
What the FDA found, and how to read the numbers
The FDA said it began its review after a 2024 study in JAMA Ophthalmology reported a higher rate of NAION among patients prescribed semaglutide. The agency said that study had “several limitations,” so it ran its own analyses.
The main one pooled 126 randomized trials with 134,253 participants. Among 78,217 patients on GLP-1 drugs, followed for a combined 156,947 patient-years, there were 10 probable NAION cases, or 6.4 per 100,000 patient-years. Among 56,036 patients on a placebo or another diabetes drug, there were five, or 3.8 per 100,000.
Those figures are worth reading two ways. In relative terms, the rate on GLP-1 drugs was about 1.7 times the comparison rate. In absolute terms, the difference is about 2.6 cases per 100,000 patient-years, or roughly one additional case for every 38,000 years of treatment. Both rates rest on very few events, 15 in all.
A second analysis, in the FDA’s Sentinel database of insurance claims, followed adults with Type 2 diabetes who started a GLP-1 drug or another common diabetes medicine between 2019 and 2024. NAION was far more common in that population, 26 to 32 cases per 100,000 patient-years across the drug groups, reflecting how diabetes, high blood pressure and sleep apnea raise the baseline risk. Compared with SGLT-2 inhibitors such as Jardiance, GLP-1 users showed no statistically significant increase (hazard ratio 1.19, with a 95 percent confidence interval of 0.91 to 1.54). Compared with DPP-4 inhibitors such as Januvia, the risk was higher (hazard ratio 1.43, interval 1.02 to 2.01).
The agency said published observational studies were “generally consistent” with its findings. It also said animal studies did not identify a mechanism by which the drugs could raise the risk, and that adverse-event reports were hard to interpret because NAION’s risk factors overlap with the conditions the drugs treat. For context, the FDA cited published estimates that NAION affects 2.3 to 10.2 adults over 50 per 100,000 each year.
What patients and doctors are told to do
The FDA advises patients to contact a health care professional right away if they notice sudden vision loss in one eye, blurred or missing areas of vision, distorted colors or reduced sharpness. Patients who have had NAION should discuss with their clinician whether to continue the drug. Doctors are told to refer suspected cases promptly to an ophthalmologist and to consider stopping the drug in patients who develop NAION “unless the benefits of treatment clearly outweigh the risk.”
Dr. Manjot Gill, an ophthalmologist at Northwestern Medicine, told NBC News that the label change was appropriate but that the condition is extremely rare. “We don’t want patients to really get overly concerned and anxious and to stop these medications,” she said.
Spokespeople for Novo Nordisk and Eli Lilly told NBC News that patient safety is their top priority. Neither company, nor the Department of Health and Human Services, which handles press inquiries for the FDA, responded to The Inquirer’s requests for comment on Monday. The drugs’ labels already carry other warnings, including a boxed warning about a possible risk of thyroid tumors.
The California picture
The label change reaches a large population. About 1 in 8 American adults said they were taking a GLP-1 drug in a KFF poll released in November 2025. In California, Medi-Cal covered more than 645,000 GLP-1 prescriptions across all uses in 2024, KFF Health News reported.
Medi-Cal stopped covering the drugs for weight loss in adults on Jan. 1, after state officials projected that cost would grow to nearly $800 million a year. It continues to cover them for Type 2 diabetes, heart and kidney disease and certain other conditions, and members under 21 remain covered, so many low-income Californians still receive the drugs through the state program.
For those patients and their doctors, the practical change is a new line on the label and a new question at checkups: any sudden change in vision now warrants a prompt eye exam.
Anjali Venkatram covers national news and the federal policies, court rulings and trends that reach California, for National News. More from Anjali Venkatram
