A federal judicial panel in the United States has ordered the consolidation of dozens of lawsuits claiming that widely used weight-loss and diabetes injections caused partial or total vision loss.
In a decision dated 15 December 2025, the US Judicial Panel on Multidistrict Litigation agreed to centralise claims against Novo Nordisk and Eli Lilly involving a rare eye condition known as non-arteritic anterior ischaemic optic neuropathy (NAION). The new multidistrict litigation (MDL) will be overseen by US District Judge Karen Spencer Marston in Philadelphia.
The lawsuits allege that medicines including Novo Nordisk’s Ozempic, Wegovy and Saxenda, and Eli Lilly’s Trulicity, can trigger NAION, a disorder linked to reduced blood flow to the optic nerve. NAION can cause sudden, painless vision loss and may be irreversible.
Court records show 30 NAION cases currently pending in federal courts, with more than 40 additional cases filed in state courts. The panel’s decision means that pre-trial proceedings – including evidence-gathering and the handling of expert testimony – can be coordinated in a single forum rather than duplicated across multiple jurisdictions.
The companies had urged the panel to fold the eye-injury complaints into an existing MDL focused on gastrointestinal injuries. Plaintiffs’ lawyers argued the vision-loss cases raise different medical and scientific issues from claims centred on digestive complications. The panel created a separate MDL, but it will still sit before Judge Marston, who has overseen the earlier proceedings.
The NAION litigation is the second major wave of US mass claims connected to the same class of drugs, known as glucagon-like peptide-1 (GLP-1) receptor agonists. These injectable medicines mimic a naturally occurring hormone involved in appetite and blood-sugar regulation, and they can slow digestion, which contributes to prolonged feelings of fullness. Developed initially for type 2 diabetes, several formulations have become widely used for obesity treatment.
According to a US Centers for Disease Control and Prevention analysis based on the 2024 National Health Interview Survey, 26.5 per cent of US adults with diagnosed diabetes reported using GLP-1 injectables in 2024 – an estimated 6.9 million people.
The blindness claims accelerated after the publication of research suggesting an association between semaglutide – the active ingredient in Ozempic and Wegovy – and increased NAION risk. A matched cohort study published in JAMA Ophthalmology in 2024 examined 16,827 patients treated for type 2 diabetes or overweight/obesity. It reported a higher NAION risk among those prescribed semaglutide compared with those prescribed non-GLP-1 alternatives.
In the type 2 diabetes cohort, the study reported a 36-month cumulative incidence of 8.9 per cent for patients prescribed semaglutide compared with 1.8 per cent for the comparison group, with a hazard ratio of 4.28. In the overweight/obesity cohort, the 36-month cumulative incidence was reported as 6.7 per cent for semaglutide versus 0.8 per cent for comparators, with a hazard ratio of 7.64. The authors stated that the findings suggest an association and that further research is required to assess causality.
The earlier gastrointestinal litigation now contains nearly 3,000 lawsuits, according to court records cited by Reuters. Those claims allege that GLP-1 medicines caused gastroparesis, sometimes described as a form of stomach paralysis affecting gastric motility.
In court filings, the companies have rejected allegations in both the gastroparesis and NAION cases. They argue digestive risks are well publicised, and that manufacturers cannot change a drug’s design without approval from the US Food and Drug Administration.
Regulators and compensation bodies outside the US have also addressed NAION as a potential safety issue. In Denmark, four patients have received compensation for vision loss alleged to be linked to Wegovy and Ozempic, according to the Danish Patient Compensation association. Reuters reported that the European Medicines Agency’s safety committee noted in June that semaglutide has been linked in very rare cases to NAION, and that Novo Nordisk updated product labels to state the condition may occur in up to 1 in 10,000 patients.
A separate Reuters report in December 2024 said Danish health authorities asked the EU’s drug regulator to review findings from Danish studies suggesting Ozempic more than doubled the risk of NAION among type 2 diabetes patients, estimating 1.5 to 2.5 additional cases per 10,000 treated people per year.
The US MDL process does not determine liability on its own, but it can set the framework for coordinated litigation and, in some cases, bellwether trials that influence settlement talks. For patients, prescribers and manufacturers, the consolidation underscores how rapidly safety concerns around GLP-1 medicines can move from clinical journals into courtrooms.
