FDA Orders Ozempic, Wegovy, Mounjaro and Zepbound to Warn of Vision Loss Risk

WASHINGTON — The US Food and Drug Administration has ordered the makers of Ozempic, Wegovy, Mounjaro and Zepbound to add a warning about a rare risk of sudden vision loss to the drugs’ labels, in the most significant safety action yet for the blockbuster GLP-1 medicines used by millions of Americans for diabetes and weight loss.

The FDA said on Monday, November 9, 2026, that the labels for the four drugs must carry information about the potential increased risk of non-arteritic anterior ischemic optic neuropathy, known as NAION, in their “warnings and precautions” section. The condition is a common cause of sudden, painless vision loss and can leave permanent damage to sight in some cases.

Key Points

• The FDA is requiring Eli Lilly’s Mounjaro and Zepbound and Novo Nordisk’s Ozempic and Wegovy to warn about a potential increased risk of NAION, a cause of sudden vision loss.
• NAION is caused by reduced blood flow to the front of the optic nerve and can lead to permanent impairment of sight in some cases.
• Europe’s regulator said last year that NAION may affect up to 1 in 10,000 people taking semaglutide for at least one year; Novo added the warning to European labels in June.
• A large 2025 study of nearly 175,000 diabetic patients found the risk of NAION more than doubled after two years of GLP-1 treatment.
• At least 4,000 consolidated legal claims allege GLP-1 drugs caused vision loss, while analysts say the drugs’ benefits should still outweigh the rare risk.

What Happened

The FDA announced on Monday, November 9, 2026, that it is requiring the four GLP-1 drugs — Eli Lilly’s Mounjaro and Zepbound and Novo Nordisk’s Ozempic and Wegovy — to add information about the potential increased risk of NAION to the “warnings and precautions” section of their labelling.

The agency said it reached the decision after evaluating clinical trial data, animal data and post-marketing data, including observational studies and case reports. The order covers the two leading drugmakers in the fast-growing GLP-1 market and the four medicines that dominate it.

Until now, US labels had carried no warning about NAION. The move brings American labelling closer to Europe, where Novo added the warning to Wegovy and Ozempic labels in June after the European Medicines Agency’s safety committee said last year that NAION may affect up to 1 in 10,000 people taking semaglutide for at least one year.

Background: How the Vision-Loss Concern Built Up

GLP-1 drugs have become some of the most widely used medicines in the United States, prescribed for type 2 diabetes and weight loss, with millions of patients taking weekly injections. Their popularity has reshaped the earnings of Eli Lilly and Novo Nordisk.

Concerns about a link to NAION have been building in the medical literature. A large 2025 study of nearly 175,000 diabetic patients on semaglutide, matched with an equal number on non-GLP-1 medicines, found the risk of NAION more than doubled after two years of GLP-1 treatment, adding to earlier observational studies and case reports.

FDA GLP-1 Vision Loss Warning: What Is NAION?

NAION, or non-arteritic anterior ischemic optic neuropathy, is a common cause of sudden, painless vision loss. It is caused by decreased blood flow to the front of the optic nerve, the bundle of fibres that carries visual signals from the eye to the brain.

The loss of vision typically comes on suddenly and without pain, and it can lead to permanent impairment of sight in some cases. Because the optic nerve does not heal easily, damage from NAION is often lasting, which is why regulators treat even a rare risk seriously when a drug is taken by millions of people.

Europe’s regulator said last year that NAION may affect up to 1 in 10,000 people taking semaglutide for at least one year. That is rare for any individual patient, but across millions of users it adds up.

Reactions and Quotes

Citi analyst Geoff Meacham said the rarity of NAION and the drugs’ weight, blood-sugar, cardiovascular, kidney and sleep-apnoea benefits should preserve a favourable benefit-risk profile. His assessment suggests the market impact may be limited.

Eli Lilly and Novo Nordisk did not immediately respond to Reuters’ requests for comment. Neither company has yet said how quickly the new warnings will appear on US packaging or whether it will change how the drugs are promoted to doctors and patients.

Why It Matters

The warning matters because of the sheer scale of GLP-1 use. Millions of Americans now take Ozempic, Wegovy, Mounjaro or Zepbound, and a risk that affects even 1 in 10,000 users can mean thousands of cases. Patients and doctors need to know what symptoms to watch for, and sudden, painless vision loss demands urgent medical attention.

It also matters for the two drugmakers. Eli Lilly and Novo Nordisk have built much of their growth on these medicines, and the labelling change adds a new safety question to a market already under scrutiny over price, supply and long-term use. The 4,000 consolidated legal claims alleging vision loss add to that pressure, even though the FDA’s action is about labelling rather than restricting access.

What Happens Next

The next step is for Eli Lilly and Novo Nordisk to update the labelling for Mounjaro, Zepbound, Ozempic and Wegovy, adding the NAION information to the “warnings and precautions” section. Doctors are likely to start discussing the eye risk with patients when they begin or renew treatment, and patients should seek urgent care if they notice sudden vision changes.

Attention will also turn to the consolidated litigation, where at least 4,000 claims allege the drugs caused vision loss.

Frequently Asked Questions

Which drugs does the FDA warning cover?

It covers Eli Lilly’s Mounjaro and Zepbound and Novo Nordisk’s Ozempic and Wegovy. All four must add information about the potential increased risk of NAION to their labelling.

What is NAION?

NAION is non-arteritic anterior ischemic optic neuropathy, a common cause of sudden, painless vision loss caused by decreased blood flow to the front of the optic nerve. It can lead to permanent impairment of sight in some cases.

How common is the risk?

Europe’s regulator said last year that NAION may affect up to 1 in 10,000 people taking semaglutide for at least one year, and a large 2025 study found the risk more than doubled after two years of GLP-1 treatment.

Should patients stop taking their GLP-1 drug?

The FDA has ordered a labelling warning, not a restriction. Patients who notice sudden vision changes should seek urgent medical care and speak to their doctor.

Why did the FDA act now?

The agency evaluated clinical trial data, animal data and post-marketing data, including observational studies and case reports. Europe confirmed the risk last year and Novo added the warning to European labels in June.

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