FDA Finds 6.4 Rare Cases per 100,000 Person-Years and Requires Warning on All GLP-1 Drugs
Key Facts
On November 9, the U.S. Food and Drug Administration required holders of applications for all GLP-1 drugs to add information about a possible increased risk of non-arteritic anterior ischemic optic neuropathy, known as NAION, to the Warnings and Precautions section of drug labels. The decision covers the entire class, including drugs made by Eli Lilly and Novo Nordisk, according to the medicines cited in Reuters coverage. The FDA said the condition is rare, but can cause a sharp, painless reduction in vision in one eye and may result in permanent vision loss. The directive turns the safety signal into a mandatory label warning, with direct guidance for patients and healthcare providers. GLP-1 drugs are used to treat type 2 diabetes, reduce weight and maintain long-term weight loss.
The FDA based its decision on an analysis of 126 randomized controlled trials of multiple GLP-1 drugs. The rate of NAION cases among patients who received these drugs was 6.4 per 100,000 person-years. In comparison groups that received a placebo or another blood sugar-lowering drug, the rate was 3.8 per 100,000 person-years. The figures show the incidence of the condition relative to the duration of treatment exposure, not the number of patients who developed it in a particular calendar year. The agency said the trial analysis included 134,253 patients and 288,879 person-years of treatment exposure. The analysis identified 15 potential cases: 10 among recipients of GLP-1 drugs and five among placebo recipients; no cases were recorded among recipients of other non-GLP-1 blood sugar-lowering drugs.
A separate observational study by the FDA compared different treatment classes among patients with type 2 diabetes who began treatment between 2019 and 2024. The study found no statistically significant increase in NAION risk when GLP-1 drugs were compared with SGLT-2 inhibitors; the hazard ratio was 1.19, with a confidence interval of 0.91 to 1.54. By contrast, it found an increase compared with DPP-4 inhibitors, with a hazard ratio of 1.43 and a confidence interval of 1.02 to 2.01. The study's findings therefore differed depending on the comparison group, while the trial analysis showed higher rates among GLP-1 recipients than in the comparison group. The agency said the warning information would address the potential risk associated with use of these drugs.
The FDA said NAION may appear as a sudden, painless loss of vision or visual impairment in one eye. The agency advises patients to tell their healthcare provider immediately if these symptoms occur and to be referred promptly to an ophthalmologist if the condition is suspected. If the condition occurs, patients should discuss with their healthcare provider whether to continue or stop taking a GLP-1 drug. Potential risk factors cited by the agency include smoking, diabetes, high blood pressure, sleep apnea, anemia and kidney disease. If the condition affects one eye, the risk of it occurring in the other eye rises.
The approved uses of the class show the breadth of the warning's impact: in addition to treating type 2 diabetes and reducing weight, additional uses for some drugs include reducing cardiovascular and kidney risks, and treating obstructive sleep apnea and metabolic dysfunction-associated steatohepatitis. In Britain, the Medicines and Healthcare products Regulatory Agency updated information on semaglutide on February 5, 2026, regarding NAION risk. The agency said the Yellow Card scheme had received 3 suspected reports by August 1, 2025, while an estimated 10.2 million packs of semaglutide had been dispensed during the five years before the update. The MHRA said it is reviewing the evidence on a possible link between the condition and other GLP-1 drugs. It also urged patients taking semaglutide who notice changes in their vision or rapid deterioration to seek care at an eye emergency service or emergency department.