Debunking the Myth: GLP-1 Medications and Claims of Sudden Blindness (NAION Risk Explained)
Personal injury lawyers—often called "ambulance chasers"—are aggressively advertising lawsuits claiming that GLP-1 medications like Ozempic, Wegovy (semaglutide), Mounjaro, and Zepbound (tirzepatide) cause sudden, permanent blindness through a rare condition called non-arteritic anterior ischemic optic neuropathy (NAION). As of late 2025, these claims have led to a new multidistrict litigation (MDL) specifically for NAION cases. While patient safety is crucial, the science paints a far less alarming picture: any potential risk is very rare, primarily linked to semaglutide in patients with type 2 diabetes, not proven as causation, and with limited or no evidence for tirzepatide. At Increase My T, we help clients optimize health with evidence-based use of these powerful medications. Here's a clear, study-backed breakdown to separate fear from facts.
What Is NAION and Who’s Really at Risk?
NAION causes sudden, painless vision loss in one eye (sometimes both) due to reduced blood flow to the optic nerve. It's the second most common optic neuropathy after glaucoma, but still rare (2-10 cases per 100,000 people yearly). Key risk factors are vascular: type 2 diabetes (damages small blood vessels), high blood pressure, high cholesterol, sleep apnea, and smoking. Diabetes alone significantly elevates risk—patients with T2D have higher odds due to microvascular damage.
The Evidence: Association, Not Proven Causation
Multiple studies (2024-2025) show an association between semaglutide and higher NAION risk in T2D patients (hazard ratios ~2-4), but emphasize confounding: these drugs are prescribed to higher-risk patients. A large 2025 U.S. cohort found a modest increase (HR 1.76) for semaglutide/tirzepatide combined vs. other antidiabetics, but absolute risk tiny (0.04% vs. 0.02%). Regulatory bodies (EMA, WHO in 2025) classify NAION as "very rare" for semaglutide, with ~1 extra case per 10,000 person-years. No definitive causation proven—experts call for more research.
Primarily in Patients with Type 2 Diabetes
The signal is strongest in T2D cohorts, where vascular risks are already elevated. In non-diabetic weight-loss users, evidence is weaker and risks lower due to better baseline vascular health.
Semaglutide vs. Tirzepatide: A Key Difference
Most early studies focused on semaglutide. Recent 2025 analyses combining both drugs show risk, but some data suggest tirzepatide (dual GLP-1/GIP agonist) has no significant independent association—potentially a safer profile for vision concerns.
The Risk Is Extremely Rare
Even in higher-risk groups, absolute numbers are tiny: ~1-2 additional cases per 10,000 users per year. Benefits (weight loss, better glucose control, reduced cardiovascular risk) far outweigh this for most.
What to Do If You're Concerned
Monitor for sudden vision changes—seek immediate care. Discuss risks/benefits with your doctor, especially if diabetic. Physician supervision is essential.
Don't Let Fear Stop Progress
GLP-1 medications remain transformative for metabolic health. Lawsuit ads exaggerate rare risks—focus on evidence. At Increase My T, we guide safe, personalized use for optimal results. Ready for evidence-based support? Schedule a free assessment today.
► Semaglutide/Tirzepatide & NAION Risk (JAMA 2025)
► EMA: NAION Very Rare for Semaglutide (2025)
► WHO on Semaglutide & NAION (2025)
*Disclaimer: Not medical advice. Consult a physician before starting any treatment.
