GLP-1 Lawsuits and Vision Loss: What Patients Should Know About NAION

GLP-1 medications have changed the way obesity and type 2 diabetes are treated. Drugs such as Wegovy, Ozempic, Zepbound, and Mounjaro have also become some of the most discussed medications in the country.

Now, a different GLP-1 story is receiving national attention.

In September 2026, news organizations reported that patients have filed lawsuits against Novo Nordisk and Eli Lilly alleging that certain GLP-1 medications were associated with a rare form of sudden vision loss called nonarteritic anterior ischemic optic neuropathy, or NAION.

The lawsuits do not prove that the medications caused these patients' vision loss. Research into a possible association is continuing, and the scientific evidence is more nuanced than many headlines suggest.

For people currently taking a GLP-1 medication, the most important message is straightforward: do not stop a prescribed medication because of a news report or lawsuit without first speaking with the healthcare professional who prescribed it.

Here is what is currently known about the GLP-1 lawsuits, NAION, and how this discussion fits into the broader range of treatments available for obesity.

Why Are GLP-1 Medications in the News?

Recent lawsuits allege that manufacturers did not adequately warn patients about a possible risk of NAION while using certain GLP-1 medications.

National reporting in September 2026 described lawsuits involving products manufactured by Novo Nordisk and Eli Lilly. Novo Nordisk makes semaglutide medications including Ozempic and Wegovy, while Eli Lilly manufactures tirzepatide medications including Mounjaro and Zepbound.

Both manufacturers have disputed the allegations.

Novo Nordisk has stated that it believes the lawsuits are without merit and that it continues to monitor the safety of its GLP-1 medications. Eli Lilly has similarly stated that patient safety is a priority and that it continues to evaluate safety information and discuss potential safety topics with regulators.

It is important to distinguish between a lawsuit alleging that a medication caused an injury and scientific evidence establishing that the medication caused that injury.

Those are not the same thing.

What Is NAION?

NAION stands for nonarteritic anterior ischemic optic neuropathy.

It occurs when blood flow to part of the optic nerve is reduced, damaging the nerve that carries visual information from the eye to the brain.

NAION typically causes sudden, painless vision loss, usually in one eye. Vision loss can be significant and is often permanent. There is currently no established treatment that reliably reverses optic nerve damage caused by NAION.

NAION is rare overall, but the risk is not identical for everyone.

Known or suspected risk factors include:

• Older age
• Type 2 diabetes
• High blood pressure
• High cholesterol
• Obstructive sleep apnea
• Smoking
• Certain anatomical characteristics of the optic nerve
• Other cardiovascular risk factors

That overlap creates an important challenge when researchers study GLP-1 medications.

Many people prescribed these medications already have diabetes, obesity, sleep apnea, hypertension, or other conditions that can independently increase the risk of NAION.

Researchers therefore have to determine whether any increased risk comes from the medication itself, the underlying health conditions of the people taking it, or a combination of factors.

What Does the Research Say About Semaglutide and Vision Loss?

Several studies have investigated a possible association between semaglutide and NAION.

The results have not all been identical.

A large multicenter study published in JAMA Ophthalmology examined data involving 37.1 million adults with type 2 diabetes, including more than 810,000 new semaglutide users.

Researchers found a small increase in the relative incidence of NAION associated with semaglutide exposure, although the results varied depending on how researchers defined NAION and which medications were used for comparison.

The researchers emphasized that additional studies were needed to better understand whether the relationship is causal.

Another large cohort study involving more than 3.3 million people with diabetes found an increased risk at certain longer-term follow-up points, while other comparisons did not show a statistically significant increase. The authors likewise concluded that additional study was needed.

More recently, a nationwide study of U.S. veterans with type 2 diabetes found approximately twice the risk of NAION among people starting semaglutide compared with those starting an SGLT2 inhibitor. Importantly, the researchers also described the absolute risk as low.

This distinction between relative risk and absolute risk matters.

A condition can become relatively more common while still remaining uncommon overall.

Is the Scientific Evidence Conclusive?

Not completely.

Some observational studies have found an association between semaglutide and NAION. Others have produced less clear results, and researchers continue to debate the magnitude of the risk and the mechanisms that might explain it.

A systematic review and meta-analysis that included more than 4.8 million participants found that the pooled observational evidence did not demonstrate a statistically significant increase in NAION when semaglutide was compared with non-GLP-1 medications. The researchers rated the certainty of that evidence as very low because results varied substantially among studies.

That is why statements such as "GLP-1 medications cause blindness" go beyond what the evidence currently supports.

The evidence is stronger for a possible association between semaglutide and NAION than it is for making broad claims about every GLP-1 medication.

Research involving tirzepatide and NAION is also more limited than the body of research involving semaglutide.

Europe Now Recognizes NAION as a Very Rare Semaglutide Side Effect

Regulators outside the United States have taken action based on the available evidence.

In 2025, the European Medicines Agency's Pharmacovigilance Risk Assessment Committee concluded that NAION should be listed as a very rare side effect of semaglutide medications, including Ozempic, Rybelsus, and Wegovy.

"Very rare" means the event may affect up to approximately 1 in 10,000 people taking semaglutide.

The EMA reported that several large epidemiological studies suggested approximately one additional case of NAION per 10,000 person-years of semaglutide treatment among adults with type 2 diabetes.

The European product information was subsequently updated to include NAION.

This regulatory decision applies specifically to semaglutide and should not automatically be generalized to every medication commonly described as a GLP-1.

What Is the FDA Saying About GLP-1s and NAION?

In the United States, the FDA has been evaluating NAION as a potential safety signal involving GLP-1 receptor agonists.

FDA safety-monitoring information lists NAION as a potential serious risk being evaluated for medications including semaglutide and tirzepatide products, among others. The FDA has stated that it is evaluating whether regulatory action is necessary.

The FDA's Sentinel Initiative also completed updated signal-identification work involving injectable semaglutide in September 2026. Sentinel is the agency's electronic system for monitoring the safety of FDA-regulated medical products after they reach the market.

At the time of this article, the U.S. regulatory approach and European approach should therefore not be treated as identical.

Drug-safety information can also change as regulators review new evidence, so patients should rely on their prescribing clinician and current FDA-approved medication information rather than older social media posts or headlines.

Should People Taking a GLP-1 Be Worried About Vision Loss?

The possibility of permanent vision loss understandably sounds alarming.

But the current evidence needs to be placed in context.

NAION remains uncommon, and researchers have not established that every person taking a GLP-1 medication faces the same risk.

Obesity and type 2 diabetes also carry significant health risks of their own. GLP-1 medications have demonstrated important benefits for many appropriately selected patients, including improvements in weight, blood sugar control, and cardiovascular outcomes.

Professional ophthalmology guidance has emphasized that studies have produced mixed results and that, even where an association has been identified, the overall magnitude of NAION risk appears low.

The risk-benefit calculation therefore needs to be individualized.

What Symptoms Require Immediate Attention?

Anyone experiencing sudden or rapidly worsening vision loss should seek prompt medical evaluation, regardless of whether they take a GLP-1 medication.

NAION commonly presents as sudden, painless loss or dimming of vision in one eye.

Other changes can include:

• Blurred or dim vision
• Loss of part of the visual field
• Reduced peripheral vision
• Changes in color perception

Do not wait for a routine appointment if vision suddenly changes.

People currently taking semaglutide or another GLP-1 medication should also tell their prescribing healthcare professional about new vision symptoms.

Should You Stop Taking Ozempic, Wegovy, Mounjaro, or Zepbound?

Do not stop a prescribed GLP-1 medication solely because of these lawsuits or news reports.

Stopping medication without medical guidance can have consequences, particularly for someone using the medication to manage diabetes or another chronic health condition.

Experts interviewed about the recent lawsuits have similarly advised patients without symptoms to continue medications as prescribed while discussing individual concerns with their physicians.

If you are concerned about NAION or have previously experienced NAION in one eye, discuss your history with the clinician managing your medication and, when appropriate, an eye specialist.

GLP-1 Medications Are One Approach to Treating Obesity

The attention surrounding these lawsuits also highlights a larger point about obesity treatment.

There is no single treatment that is appropriate for every patient.

Depending on a person's BMI, obesity-related medical conditions, health history, previous weight-management efforts, preferences, and other factors, treatment may include:

• Nutrition and behavioral interventions
• Physical activity
• Obesity-management medications
• Metabolic and bariatric surgery
• A combination of approaches over time

Medication and surgery should not be viewed as competing trends.

They are different tools used within modern obesity medicine.

In fact, some patients use GLP-1 medications before or after bariatric surgery as part of an individualized long-term treatment plan.

Where Does Gastric Sleeve Surgery Fit?

Sleeve gastrectomy, commonly called gastric sleeve surgery, is an established metabolic and bariatric surgical procedure.

During a sleeve gastrectomy, a large portion of the stomach is removed, leaving a smaller sleeve-shaped stomach.

The procedure changes the amount of food the stomach can hold and also affects biological signals involved in hunger, fullness, and metabolism.

The American Society for Metabolic and Bariatric Surgery recognizes sleeve gastrectomy as an evidence-based metabolic and bariatric surgical procedure.

Unlike taking a medication, sleeve gastrectomy is a surgical intervention and comes with its own risks, benefits, eligibility criteria, nutritional requirements, and need for long-term follow-up.

It is therefore not accurate to say that gastric sleeve surgery is simply a "safer version" of a GLP-1 medication.

They are fundamentally different treatments.

Gastric Sleeve vs. GLP-1 Medication: They Are Different Decisions

People considering obesity treatment frequently ask whether they should use a GLP-1 medication or pursue bariatric surgery.

There is no universal answer.

GLP-1 medications are nonsurgical treatments that may produce clinically meaningful weight loss while the medication is being used. They also have medication-specific side effects, contraindications, costs, and considerations surrounding long-term treatment.

Sleeve gastrectomy is a surgical treatment that can produce substantial, durable weight loss and improvement in obesity-related conditions for appropriately selected patients. It also requires an operation, recovery period, dietary changes, vitamin and mineral monitoring, and long-term medical follow-up.

Current bariatric guidelines emphasize matching treatment to the individual rather than recommending one approach for everyone.

The American Society for Metabolic and Bariatric Surgery currently recognizes obesity-management medications and metabolic and bariatric surgery as parts of a broader continuum of obesity care.

Can You Have Bariatric Surgery After Taking a GLP-1?

Yes, previous GLP-1 treatment does not automatically prevent someone from undergoing bariatric surgery.

A 2026 study presented at the American Society for Metabolic and Bariatric Surgery annual meeting examined patients who used semaglutide or tirzepatide before metabolic and bariatric surgery.

Patients who subsequently underwent sleeve gastrectomy achieved approximately 20% total weight loss in that analysis. The researchers reported that prior GLP-1 use did not appear to compromise the effectiveness of surgery.

These findings do not mean everyone taking a GLP-1 should transition to surgery.

They do reinforce that obesity treatment can evolve over time.

A person may try medication first, consider surgery later, or use medication as part of care before or after a procedure depending on medical circumstances.

When Is Bariatric Surgery Considered?

Current ASMBS and International Federation for the Surgery of Obesity and Metabolic Disorders guidelines recommend metabolic and bariatric surgery for people with a BMI of 35 or higher, regardless of whether obesity-related health conditions are present.

Surgery is also recommended for people with type 2 diabetes and a BMI of 30 or higher and can be considered for people with a BMI between 30 and 34.9 when nonsurgical treatment has not produced substantial or durable improvement.

Eligibility still requires an individual medical evaluation.

BMI alone does not determine which treatment is best for a particular person.

What the GLP-1 Lawsuits Do and Do Not Tell Us

The recent lawsuits deserve attention, particularly because they involve allegations of permanent vision loss. But lawsuits are not clinical trials, and the existence of a lawsuit does not establish that a medication caused an injury.

At this point, the evidence supports a more measured interpretation. Some studies have identified a possible association between semaglutide and NAION, but the absolute risk appears to be low. European regulators classify NAION as a very rare adverse effect of semaglutide, while the FDA continues to monitor the potential safety signal in the United States. The evidence is also not equally strong for every GLP-1 medication.

At the same time, a potential adverse effect does not erase the established benefits these medications can provide to appropriately selected patients. Obesity itself is a chronic disease with significant health consequences, so treatment decisions should consider both the risks of therapy and the risks of leaving obesity inadequately treated.

Frequently Asked Questions About GLP-1s and Vision Loss

Can Ozempic or Wegovy cause NAION?

Research has found an association between semaglutide, the active ingredient in Ozempic and Wegovy, and NAION in some studies. The European Medicines Agency classifies NAION as a very rare adverse effect of semaglutide. Research continues to clarify the magnitude of the risk, particularly in the United States.

Does NAION affect everyone taking a GLP-1?

No. NAION is uncommon, and several independent risk factors can contribute to the condition. These include age, diabetes, cardiovascular risk factors, sleep apnea, and certain characteristics of the optic nerve.

Are the GLP-1 lawsuits proof that the drugs caused vision loss?

No. Lawsuits contain allegations that must be evaluated through the legal process. They do not by themselves establish medical causation.

Should I stop my GLP-1 because of the lawsuits?

Do not stop a prescribed medication based solely on a lawsuit or news report. Discuss your individual risks, benefits, and concerns with the healthcare professional prescribing the medication.

The Bottom Line

The recent GLP-1 lawsuits have brought new attention to a rare but serious eye condition called NAION.

There is legitimate scientific research examining a possible association, particularly with semaglutide. European regulators have already classified NAION as a very rare semaglutide side effect, while U.S. safety monitoring continues.

That does not mean GLP-1 medications should be considered universally unsafe.

It also does not mean bariatric surgery should automatically replace medication.

Obesity is a chronic disease, and both medication and metabolic and bariatric surgery can have a role in treatment.

The right approach depends on your health, treatment history, goals, medical risks, and the recommendations of qualified healthcare professionals.

Considering Bariatric Surgery?

If you are exploring long-term treatment options for obesity, a bariatric consultation can help you understand whether metabolic and bariatric surgery may be appropriate for your health and medical history.

BASS Bariatric Surgery offers gastric sleeve surgery and other bariatric care for appropriately selected patients in Northern California.

A bariatric evaluation can help you understand eligibility, expected outcomes, surgical risks, recovery, nutrition requirements, and how surgery may fit into your overall weight-management plan. Request a bariatric surgery consultation today!