Non-arteritic anterior ischaemic optic neuropathy (NAION) is a rare but severe eye disorder involving sudden blood-flow disruption to the optic nerve head that can result in permanent visual impairment including blindness. No treatment has been shown to improve visual acuity outcomes after NAION onset.
On this site, NAION appears through the class-wide GLP-1 receptor agonist safety signal that emerged in 2024-2025 pharmacovigilance data. The UK's MHRA issued a Drug Safety Update on semaglutide and NAION on February 5, 2026. Australia's Therapeutics Goods Administration (TGA) issued a class-wide GLP-1 receptor agonist product warning update on July 25, 2026 covering Trulicity (dulaglutide), Ozempic (semaglutide), Wegovy (semaglutide), Mounjaro (tirzepatide), and Saxenda (liraglutide). The TGA Advisory Committee on Medicines concluded that current evidence supports the NAION signal for semaglutide but not for dulaglutide or tirzepatide. A search of the Australian Database of Adverse Event Notifications (DAEN) found 36 cases of optic ischaemic neuropathy with GLP-1 RAs, including 23 for semaglutide, 10 for tirzepatide, and 3 for liraglutide.
The FDA followed on November 9, 2026, requiring every GLP-1 receptor agonist, from Byetta and Victoza to Ozempic, Wegovy, Mounjaro, Zepbound, and Foundayo, to add NAION to the Warnings and Precautions section of its label. The agency called the risk potential: in its pooled analysis of 126 trials, probable NAION occurred at 6.4 vs. 3.8 events per 100,000 person-years, and a Sentinel study found a hazard ratio of 1.43 against DPP-4 inhibitors but no significant difference against SGLT2 inhibitors.
Stories here cover regulatory action on NAION signal, ongoing pharmacovigilance analyses, and clinical guidance for patients on GLP-1 therapy. Patient guidance across TGA, MHRA, and FDA advises seeking urgent medical attention for any sudden vision loss including partial loss of vision while on GLP-1 receptor agonists. See #glp-1, #semaglutide, and #pharmacovigilance for adjacent threads.
The FDA said on November 9 that it is requiring all GLP-1 receptor agonists, including Ozempic, Wegovy, Mounjaro, Zepbound, and Foundayo, to add nonarteritic anterior ischemic optic neuropathy (NAION) to the Warnings and Precautions section of their labels, concluding there is a "potential increased risk of rare NAION events." In a pooled analysis of 126 randomized trials with 134,253 patients, probable NAION occurred at 6.4 events per 100,000 person-years on GLP-1 drugs vs. 3.8 on placebo or other glucose-lowering drugs (10 events vs. 5, all 5 on placebo), and an FDA Sentinel study in type 2 diabetes found a hazard ratio of 1.43 vs. DPP-4 inhibitors (95% CI 1.02 to 2.01) but no significant difference vs. SGLT2 inhibitors. The agency tells patients to seek care right away for sudden, painless vision loss in one eye and tells clinicians to consider stopping the drug in patients who develop NAION.
Australia's Therapeutics Goods Administration (TGA) issued a class-wide product warning update Saturday July 25, 2026 for GLP-1 receptor agonists on non-arteritic anterior ischaemic optic neuropathy (NAION), a rare but severe form of eye disorder that may result in permanent visual impairment including blindness. No treatment has been shown to improve visual acuity outcomes after NAION onset. The label update applies across all five GLP-1 RA products currently marketed in Australia: Trulicity (dulaglutide, Eli Lilly), Ozempic (semaglutide, Novo Nordisk), Wegovy (semaglutide, Novo Nordisk), Mounjaro (tirzepatide, Eli Lilly), and Saxenda (liraglutide, Novo Nordisk). The Advisory Committee on Medicines concluded that the current evidence supports the signal for semaglutide but not for dulaglutide or tirzepatide. A search of the Australian Database of Adverse Event Notifications (DAEN) found 36 cases of optic ischaemic neuropathy with GLP-1 RAs, including 23 for semaglutide, 10 for tirzepatide, and 3 for liraglutide. Patient guidance advises seeking urgent medical attention for any sudden vision loss including partial loss of vision. The Australian action follows the UK MHRA Drug Safety Update on semaglutide and NAION issued February 5, 2026.
Two federal multidistrict litigations against GLP-1 manufacturers continue to expand. MDL 3094 — In Re: Glucagon-Like Peptide-1 Receptor Agonists Products Liability Litigation — now consolidates 3,636 cases alleging gastrointestinal injury, including gastroparesis and severe vomiting. MDL 3163, created December 15, 2025 after the JPML approved consolidation of vision-loss cases tied to non-arteritic anterior ischemic optic neuropathy (NAION), holds 86 cases as of May 6. Both sit before Judge Karen S. Marston in the Eastern District of Pennsylvania; no bellwether trial has been scheduled and no global settlement is in negotiation.
Over 3,546 lawsuits are now consolidated in two federal MDLs — one for gastroparesis and one for NAION vision loss. On March 3, a federal judge appointed lead counsel for the NAION MDL. Studies show semaglutide users face a fourfold increase in NAION risk, with vision loss claims now generating more legal attention than earlier gastroparesis cases.