This fat jab linked to blindness risk
Weight-loss injections used by millions of underweight people may increase the risk of a rare eye condition that can cause permanent blindness.
Scientists have warned that people taking Wegovy are at the highest risk of developing the debilitating condition compared to those taking similar drugs.
The powerful injection contains semaglutide, the same active ingredient found in Ozempic, which has been hailed as a breakthrough treatment for obesity and Type 2 diabetes.
But scientists say the drug may also increase the risk of non-arteritic ischemic anterior optic neuropathy (NAION), sometimes called “eye sting.”
This condition occurs when the blood vessels feeding the optic nerve become blocked, depriving the nerve of oxygen and causing permanent damage.
Researchers found that people taking Wegovy were five times more likely to develop this condition than those taking Ozempic.
The study also suggested that men are nearly three times more likely than women to develop the disorder, medically known as ischemic optic neuropathy.
Experts from the University of Ottawa analyzed reports submitted to the U.S. Food and Drug Administration Adverse Event Reporting System between 2017 and 2024.
Of more than 30 million safety alerts, 31,774 were related to semaglutide. Approximately 3,070 people were linked to Wegovy and more than 20,000 were linked to Ozempic.
Despite fewer reports overall, Wegovy showed the strongest link to eye discomfort.
Writing in the British Journal of Ophthalmology, the researchers said the findings “highlight a potential dose-related safety concern” related to semaglutide.
They added: “Overall, the risk of ION appears to be dose- and formulation-dependent and is highest with Wegovy.”
Interestingly, the once-daily semaglutide tablet Rybelsus was not linked to this condition.
Experts believe this may be due to slower absorption of the drug compared to injectable versions.
Pharmaceutical giant Novo Nordisk, which produces all three drugs, said patient safety remains the “number one priority”.
A spokesman said: “We take any reports of adverse events resulting from the use of our medicines very seriously.”
The firm added that safety leaflets across the UK and EU have now been updated to include the risk of NAION.
This condition affects approximately one in 10,000 people and currently has no cure. Victims usually experience sudden, painless loss of vision in one eye, which is often first noticed when they wake up.
