The popular weight-loss drug Wegovy (semaglutide) may carry a significantly higher risk of ischaemic optic neuropathy (ION), a condition often referred to as an “eye stroke,” compared to other semaglutide formulations like Ozempic, according to emerging data. This rare but serious condition can lead to sudden, irreversible vision loss. Health authorities are actively investigating the potential link and updating product information to reflect the increased risk associated with the higher-dose medication.
Ischaemic optic neuropathy occurs when blood flow to the optic nerve is disrupted, potentially causing sudden, painless vision loss. While the absolute risk remains low, the data suggest a disproportionate impact with Wegovy, prompting increased scrutiny from regulatory bodies like the European Medicines Agency (EMA) and the World Health Organization (WHO). Understanding the potential risks associated with semaglutide medications is crucial for both patients and healthcare professionals.
Wegovy’s Risk Profile: A Closer Appear
A recent observational study, the first global, population-based analysis of its kind, compared the risk of ION among users of different semaglutide formulations. The findings indicate that the odds of developing ION were nearly five times higher among individuals using Wegovy compared to those using Ozempic. The study analyzed data from over 30 million reports across diabetes and obesity populations [1]. The risk appears to be greater in men, with the odds being approximately three times higher compared to women [1].
The EMA’s Pharmacovigilance Risk Assessment Committee (PRAC) has reviewed available data, including clinical trials and post-marketing surveillance and concluded that ION is a very rare side effect of semaglutide, potentially affecting up to 1 in 10,000 users. The EMA has recommended updating the product information for Wegovy, Ozempic®, and Rybelsus® to include NAION (non-arteritic anterior ischemic optic neuropathy) as a side effect, classified as very rare [3].
What is Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION)?
NAION is a leading cause of vision loss in adults, second only to glaucoma. It typically presents as a sudden, painless loss of vision in one eye, often described as blurring or cloudiness, accompanied by swelling of the optic disc [3]. Unfortunately, vision loss resulting from NAION is generally irreversible, and there is currently no proven effective treatment available [3].
Semaglutide is a glucagon-like peptide-1 receptor agonist (GLP-1RA) used to treat type 2 diabetes, and obesity. The WHO and other health agencies are alerting healthcare professionals and regulatory authorities to the potential risk associated with its utilize [3]. The Medicines and Healthcare products Regulatory Agency (MHRA) in the UK similarly issued a safety update in February 2026 regarding the risk of NAION associated with semaglutide [4].
Recommendations for Patients and Healthcare Providers
If patients experience a sudden loss of vision or rapidly worsening eyesight while taking semaglutide, they should contact their doctor immediately [3]. If NAION is confirmed, treatment with semaglutide should be discontinued [3]. Healthcare professionals are advised to urgently refer patients reporting sudden vision loss for specialist ophthalmological examination [4]. It’s also important to inquire about semaglutide use, even if it’s privately prescribed and may not appear on a patient’s medical history [4].
The WHO Advisory Committee on Safety of Medicinal Products (ACSoMP) has also evaluated the evidence and concluded that the Risk Management Plan for semaglutide should be revised to include NAION as a potential risk, along with any necessary additional pharmacovigilance activities [3].
This safety alert is being issued due to the widespread global use of semaglutide and the serious nature of NAION. Continued monitoring and reporting of adverse events are essential to further understand the risk and ensure patient safety.
Disclaimer: This article provides informational content only and is not intended to be a substitute for professional medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of any medical condition.
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