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US FDA adds rare eye-condition warning to GLP-1 drugs

Drugs such as Ozempic, Wegovy and Mounjaro must now mention a potential increased risk of NAION, a rare cause of sudden vision loss.

By Delulublog Desk · · 4 min read

TL;DR in 30 sec

  • The US Food and Drug Administration (FDA) said on Monday that all GLP-1 drugs, including Ozempic, Wegovy, Mounjaro and Zepbound, must carry a warning about a potential increased risk of NAION, a rare eye condition, CNN reported.
  • In the FDA’s analysis of 126 clinical trials, NAION occurred at 6.4 events per 100,000 patient-years with GLP-1 drugs against 3.8 with comparison treatments, BioSpace reported.
  • The FDA could not identify how the drugs might raise the risk, NBC News reported, and Novo Nordisk said the data do not establish cause and effect, according to CNN.
  • Generic semaglutide, the medicine in Ozempic and Wegovy, went on sale in India in March 2026 after its patent expired, Business Today reported.
A medicine injection pen lies on a desk beside a label card with a warning triangle, while a large stylised eye, partly blurred, looks on from the wall.
Illustration

What happened

The US FDA has told the makers of all GLP-1 drugs to add a new warning to their labels, CNN reported. The warning, in the “warnings and precautions” section, covers a potential increased risk of non-arteritic anterior ischemic optic neuropathy (NAION), according to CNN.

The FDA announced the move on Monday, 9 November, The Hindu reported.

GLP-1 drugs are medicines for type 2 diabetes and obesity. The order covers Eli Lilly’s Mounjaro and Zepbound and Novo Nordisk’s Ozempic and Wegovy, among others, CNN reported. BioSpace said the FDA listed twelve approved drugs that must make the change.

“Patients and caregivers should be aware of a potential increased risk of NAION, a rare condition that can result in acute, painless, decreased vision in one eye, including permanent vision loss,” the FDA said, according to NBC News.

Why it matters for India 🇮🇳

Semaglutide prices in India fell sharply this year. Several Indian drug makers launched generic semaglutide in March 2026, a day after the patent expired, with prices falling by as much as 90% from the branded version, Business Today reported.

An estimated 101.3 million people in India live with diabetes, according to the ICMR-INDIAB study cited by Business Today. About 2 lakh patients in India were on GLP-1 therapy at the time, according to Novo Nordisk India, the same report said.

The sources reviewed carry no statement from India’s drug regulator on the FDA’s move.

Background

NAION is caused by reduced blood flow to the front part of the optic nerve, CNN reported, though the underlying cause is not fully understood. The optic nerve carries signals from the eye to the brain, NBC News explained.

Symptoms include blurred vision, blind spots and distorted colours. Patients who notice them should contact a health care professional immediately, the FDA said, according to The Hindu.

The FDA began its review after a 2024 study in JAMA Ophthalmology found that diabetes patients prescribed semaglutide were four times as likely to develop NAION as those not prescribed it, NBC News reported.

The FDA looked at clinical trial data, animal data, case reports and observational studies, CNN reported. Across 126 trials, it found 15 probable NAION cases, BioSpace reported: 10 in patients on GLP-1 drugs, five on placebo and none on other diabetes medicines.

The FDA also ran its own study of real-world data. It found no higher risk with GLP-1 drugs than with SGLT-2 inhibitors, but a higher risk than with DPP-4 inhibitors, two other kinds of diabetes medicine, according to BioSpace.

Last year, a safety committee of the European Medicines Agency said NAION may affect up to 1 in 10,000 people taking semaglutide for at least a year, CNN reported.

Different perspectives

Novo Nordisk said it “continues to believe the data do not establish a cause-and-effect relationship”, and that it remains confident in its medicines’ benefit-risk profile, CNN reported. Eli Lilly said the FDA’s communication covers the whole drug class and has no findings specific to Lilly medicines, and that it would respond to the FDA promptly, according to CNN.

Risk factors for NAION, such as type 2 diabetes, obesity, sleep apnoea and high blood pressure, overlap with the conditions of many people who take GLP-1 drugs, NBC News reported.

Dr Manjot Gill, an ophthalmologist at Northwestern Medicine in Chicago, told NBC News the warning was appropriate and was mainly about public awareness, since the condition is extremely rare. Analysts at BMO and Citi said they expected little effect on prescribing, given the rarity of NAION, BioSpace and CNN reported.

Open questions 🤔

  • Will India’s drug regulator ask for a similar warning on GLP-1 drugs sold in India?
  • Do GLP-1 drugs cause NAION, or do the two only appear together because they share risk factors?
  • When will the updated US labels appear on the twelve drugs?

What to watch next

Eli Lilly said it is evaluating the FDA’s update and will respond to the agency promptly, CNN reported. The reports reviewed give no date for the label changes.

Sources & Credits

This article is based on the following reporting and official sources. Credit to each original publisher.

  1. US FDA orders new eye risk warnings for Ozempic, Zepbound · CNN · accessed
  2. FDA orders new warning on GLP-1s over rare eye condition linked to sudden blindness · NBC News · accessed
  3. FDA orders class-wide GLP-1 label update to include potential risk for rare eye disease · BioSpace · accessed
  4. FDA adds rare vision-loss warning to popular obesity, diabetes drugs · The Hindu · accessed
  5. Generic semaglutide hits India; prices fall 90% as companies compete for diabetic patients · Business Today · accessed