Hundreds of Lawsuits Target GLP-1 Drugmakers Over Alleged Vision Loss

GLP-1 Makers Face Vision Loss Lawsuits

Hundreds of lawsuits are now tied to claims that popular GLP-1 medications may be associated with a rare form of sudden vision loss, putting drugmakers Novo Nordisk and Eli Lilly under growing legal scrutiny. The litigation centers on a condition called non-arteritic anterior ischemic optic neuropathy, commonly known as NAION. The condition occurs when blood flow to part of the optic nerve is disrupted and can cause sudden, painless vision loss, typically in one eye. In some cases, the resulting vision impairment can be permanent.

More Than 200 Federal Cases

The federal cases have been consolidated into multidistrict litigation, or MDL, in the U.S. District Court for the Eastern District of Pennsylvania. The litigation is known as MDL No. 3163 and is overseen by U.S. District Judge Karen S. Marston. As of September 1, 2026, the MDL had 216 pending federal actions involving allegations that GLP-1 medications were linked to NAION. The number does not necessarily represent every lawsuit filed nationwide because additional cases can proceed in state courts or elsewhere. The federal litigation has involved medications including Ozempic, Wegovy and Saxenda from Novo Nordisk, as well as Trulicity from Eli Lilly. Other GLP-1 medications, including Mounjaro and Zepbound, have also been named in related litigation.

What The Lawsuits Allege

The lawsuits generally claim that patients developed NAION after using GLP-1 medications and that the manufacturers failed to adequately warn patients and medical professionals about the potential risk. The cases raise questions involving the drugs’ development, manufacturing, testing, regulatory history, promotion and labeling, as well as whether the medications can cause NAION. Plaintiffs have brought claims including failure to warn, design defect and breach of warranties. The creation of an MDL does not mean a court has determined that the medications caused the alleged injuries. An MDL is a legal procedure used to coordinate similar federal cases during pretrial proceedings. Individual claims can ultimately have different outcomes.

The Medical Evidence Is Still Being Examined

The potential connection between GLP-1 medications and NAION has been studied for several years, but regulators and researchers have continued to evaluate the available evidence. European regulators determined in 2025 that NAION should be listed as a very rare side effect of medicines containing semaglutide, the active ingredient in Ozempic, Wegovy and Rybelsus. The regulators said available evidence suggested approximately one additional case of NAION per 10,000 person-years of treatment. Several large epidemiological studies also indicated an approximately twofold increase in risk among adults with Type 2 diabetes taking semaglutide. U.S. regulators have also been evaluating whether additional regulatory action is necessary regarding NAION and several GLP-1 medications.

Drugmakers Dispute The Allegations

Novo Nordisk and Eli Lilly have disputed allegations that their medications caused patients’ vision injuries. The companies have maintained that they take reports of adverse events seriously while defending themselves against the lawsuits. The allegations remain disputed, and the litigation is continuing.

What Patients Should Know

The lawsuits do not mean that everyone taking a GLP-1 medication will experience vision loss. NAION is considered rare, and regulators continue to distinguish the potential risk from the much larger population of people using GLP-1 medications. Anyone taking a GLP-1 medication who experiences sudden or rapidly worsening vision should seek medical attention promptly. Regulators have specifically advised patients experiencing sudden vision loss to contact a medical professional without delay. The legal cases are still developing. At the center of the litigation is whether certain GLP-1 medications increase the risk of NAION and, if so, how significant that risk may be. The outcome could affect drug warnings, labeling and future litigation involving widely prescribed medications used for diabetes and weight management.