US regulator orders weight-loss drug makers to add rare blindness risk warning

New labelling requirement

The Food and Drug Administration said on Monday, 9 November 2026, that makers of GLP-1 medicines must add a warning about a possible higher risk of blindness to their labels. The agency named Eli Lilly and Novo Nordisk, along with other holders of applications for these drugs, as companies that must make the change. The condition is non-arteritic anterior ischemic optic neuropathy, or NAION, which the FDA said can bring on sudden, painless vision loss in one eye that may be permanent. The agency said it was informing patients and healthcare providers about the potential risk.

Basis for the decision

The FDA said NAION cases have been reported for every GLP-1 product currently on the market. After its own review, the agency concluded there is a potential increase in rare NAION events among people taking these drugs. Monday's notice drew on a July 2024 article in the peer-reviewed journal JAMA Ophthalmology about NAION risk among GLP-1 users. The FDA said that study had several limitations, yet it judged the possible risk still needed further assessment. Afterward, the agency reviewed clinical trial results, animal findings, post-marketing records, observational research and case reports. It also carried out a meta-analysis of clinical trials.

Company responses

Novo Nordisk said patient safety was its top priority and that it would keep monitoring its medicines and work with health authorities worldwide. A company spokesperson added:

“We recognise that Naion can have a profound impact on patients and their families.”

The spokesperson also said the company remained confident that the benefits of GLP-1 drugs outweigh their risks. Eli Lilly had not commented at the time of the announcement.

Usage and European precedent

About 28 million Americans are taking these drugs, according to a July Gallup poll. The requirement covers Novo Nordisk's Wegovy and Ozempic and Eli Lilly's Mounjaro and Zepbound. The European Medicines Agency became the first regulator to confirm last year that Novo Nordisk's medicines can trigger the condition in very rare cases. It estimated that up to one in 10,000 patients who take semaglutide for at least a year could be affected. A large study published in 2025, covering around 175,000 people with diabetes, found that the risk more than doubled after two years of treatment with a GLP-1 drug compared with other diabetes medicines.