You’re going to want to keep an eye on this.
The Food and Drug Administration warned Monday that GLP-1 drugs may raise the risk of a rare but serious condition that can lead to permanent blindness.
The agency is ordering drugmakers to update safety labels on their popular weight-loss and diabetes treatments, alerting patients and health care providers to the potential danger.
The condition, known as nonarteritic anterior ischemic optic neuropathy (NAION), is triggered by a sudden drop in blood flow to the front of the optic nerve.
Warning signs may include painless vision loss in one eye — which patients may first notice upon waking — as well as blurred vision, missing patches of sight, distorted colors and hazy spots affecting central vision.
“Patients should contact their health care professional right away if they have any of these symptoms,” the FDA wrote in a drug safety communication issued Nov. 9.
There is currently no proven treatment to cure or reverse vision loss caused by NAION, which can lead to blindness.
The warning follows a 2024 study that found diabetes patients taking semaglutide — the active ingredient in GLP-1 drugs Ozempic and Wegovy — were four times more likely to develop NAION than those who weren’t prescribed the medication
“Although FDA identified several limitations of this study, the agency determined that further assessment of the potential increased risk for NAION was warranted,” the agency wrote.
The FDA said it conducted a “comprehensive evaluation” of available clinical trial data, animal data and post-marketing information, including observational studies and case reports.
The agency found that NAION cases had been reported across all currently marketed GLP-1 products.
However, it said those reports were difficult to interpret because NAION risk factors often overlap with conditions common among patients taking the medications.
The FDA also said it was unable to identify a mechanism explaining how GLP-1 drugs might increase the risk of the eye condition.
Still, based on the available evidence, the agency “concluded that there is a potential increased risk of rare NAION events” among GLP-1 users.
The safety warning is being passed down as GLP-1s have become some of the most sought-after drugs in the country.
The treatments work by mimicking hormones produced in the gut in response to eating, helping regulate appetite, digestion and blood sugar.
The class includes blockbuster treatments such as Ozempic, Wegovy, Zepbound and Mounjaro, which are widely prescribed to treat Type 2 diabetes and help patients lose excess weight.
Some GLP-1 drugs have also been approved for additional uses, including reducing the risk of major cardiovascular events and worsening kidney disease. Others have been cleared to treat obstructive sleep apnea and liver disease.
Researchers are also investigating the medications for a range of other potential uses, including treating substance use disorders and preventing neurodegenerative disease.
But their meteoric rise hasn’t been without side effects.
GLP-1 users frequently report gastrointestinal problems, including nausea, vomiting, diarrhea and constipation. Serious gallbladder problems, pancreatitis and kidney injury have also been reported, though they are less common.
The drug class also carries a boxed warning about the potential risk of thyroid tumors.
Now, the FDA is urging health care providers to tell patients taking GLP-1s to immediately report any new, painless vision loss, visual field deficits or other visual disturbances in one eye.
“If NAION is suspected, promptly refer the patient to an ophthalmologist for evaluation,” the agency wrote. “Consider discontinuing the GLP-1 RA in patients who develop NAION, unless the benefits of treatment clearly outweigh the risk.”
