The Medicines and Healthcare products Regulatory Agency (MHRA)
has today (5 February 2026) updated product information for
healthcare professionals and patients regarding the risk of the
very rare occurrence of non-arteritic anterior ischemic optic
neuropathy (NAION) in patients taking semaglutide.
Semaglutide is a glucagon-like peptide-1 receptor agonist
(GLP-1RA) sold under the brand names Ozempic and Rybelsus,
prescribed for patients with type 2 diabetes; and also as Wegovy,
which is indicated for weight management and cardiovascular risk
reduction in patients who are overweight or obese.
NAION is an extremely rare ischemic event which occurs due to
reduced blood flow to the front portion of the optic nerve which
typically causes sudden, painless vision loss in one eye.
Patients who have experienced NAION describe it as a blurring or
cloudiness of vision.
Patients taking semaglutide who notice a change in their
eyesight, such as sudden impairment to their vision, or if their
eyesight gets worse very quickly in one or both eyes, should
urgently attend eye casualty (if available in the area) or
A&E.
Dr Alison Cave, MHRA's Chief Safety Officer
said:
“Patient safety is the MHRA's top priority and we continually
monitor the safety and efficacy of all licensed medicines.
“While the potential risk of NAION for patients prescribed
semaglutide is extremely small, it is important that patients and
healthcare professionals are alert to the associated symptoms.
“If you, or someone you care for, is taking semaglutide and you
notice sudden loss of vision in one eye, then we advise you to
urgently attend eye casualty (if available in your area) or
A&E and report it via our https://yellowcard.mhra.gov.uk/
scheme.”
Guidance on potential side effects of semaglutide and on its safe
and effective use is available here.
