Health officials have issued a warning to weight loss jab users after a rare eye condition was linked to a popular medication used by thousands11:28, 02 Jun 2026Millions of people use weight loss and diabetes jabs every year, but health officials are warning patients to be alert to one potentially serious symptom that could affect their eyesight.‌The alert concerns medicines containing semaglutide, including Wegovy, Ozempic and Rybelsus. According to the Medicines and Healthcare products Regulatory Agency (MHRA), users who experience sudden vision problems should seek urgent medical attention.‌It relates to a rare eye condition known as non-arteritic anterior ischemic optic neuropathy (NAION). The condition affects the optic nerve and can lead to sudden sight loss, which in some cases may be permanent.‌According to the MHRA, patients taking semaglutide should seek immediate medical help if they experience "sudden loss or rapid worsening of eyesight". The regulator said treatment should be stopped if NAION is confirmed.NAION occurs when blood flow to the optic nerve is reduced, damaging the nerve tissue responsible for transmitting visual information to the brain. According to Manchester Royal Eye Hospital, the condition is sometimes described as a "small stroke" of the optic nerve, although it does not cause the typical symptoms associated with a stroke.‌The hospital says NAION is one of the most common causes of sudden optic nerve-related vision loss in people over the age of 50. According to its patient guidance, risk factors can include diabetes, high blood pressure and smoking.Symptoms typically develop suddenly and without pain. Manchester Royal Eye Hospital says patients often notice blurred, cloudy or missing areas in their vision, usually affecting one eye.The MHRA's warning follows a review of evidence examining the safety of semaglutide medicines. According to the regulator, several large epidemiological studies found that adults with type 2 diabetes taking semaglutide had around twice the risk of developing NAION compared with those not taking the drug.‌However, health officials stressed the condition remains very rare. The MHRA classifies the side effect as "very rare", meaning it is estimated to affect up to one in 10,000 people taking the medication.Semaglutide is the active ingredient in Wegovy, which is prescribed for weight loss, as well as Ozempic and Rybelsus, which are used to treat type 2 diabetes. Prescriptions for the drugs have risen sharply in recent years as demand for weight management treatments has grown.Article continues belowThe MHRA emphasised that patients should not stop taking prescribed medication without speaking to a healthcare professional. The regulator said the overall benefits of semaglutide continue to outweigh the known risks when used as authorised.Research published by the National Centre for Biotechnology Information (NCBI) describes NAION as one of the leading causes of sudden vision loss in older adults. Researchers said the condition most commonly presents as sudden, painless vision loss in one eye, often noticed upon waking.Anyone taking semaglutide who experiences sudden vision loss, blurred vision or rapidly worsening eyesight is advised to seek urgent medical assessment. Early investigation can help doctors determine the cause of symptoms and whether treatment should continue.