Weight Loss Injection Wegovy May Carry Elevated Risk of Sudden Vision Loss
New analysis has raised significant safety concerns regarding the popular weight loss medication Wegovy, suggesting it may present a higher risk of sudden sight loss compared to similar pharmaceutical treatments. The study, published in the British Journal of Ophthalmology, indicates that this risk appears to be dose-dependent, with Wegovy showing the strongest association among medications containing the active ingredient semaglutide.
Study Reveals Disturbing Link to Eye Strokes
Researchers examined the connection between semaglutide-based medications and ischaemic optic neuropathy (ION), commonly referred to as an eye stroke. This serious condition causes sudden vision impairment due to reduced blood flow to the optic nerve. The investigation analyzed over 30 million adverse event reports submitted to the US Food and Drug Administration's monitoring system between December 2017 and December 2024.
Among these reports, 31,774 involved semaglutide medications. While Ozempic accounted for 20,608 reports (having been approved earlier in 2017), Wegovy—launched in 2021—was linked to 3,070 reports. Despite this numerical difference, statistical analysis revealed Wegovy demonstrated a stronger association with eye stroke incidents.
Dose-Dependent Risk and Gender Disparities
The research uncovered several critical findings regarding risk factors:
- Wegovy showed nearly five times higher odds of ION compared to Ozempic
- Men were three times more likely than women to experience these eye strokes
- The oral medication Rybelsus showed no reported associations with ION
"Overall, ION risk appears dose and formulation dependent, and highest with Wegovy," the researchers stated. "Ozempic's earlier approval resulted in more reports than Wegovy, yet Wegovy showed the stronger signal."
Understanding the Semaglutide Family
Wegovy, Ozempic, and Rybelsus all contain semaglutide as their active ingredient but differ significantly in their applications and dosages:
- Wegovy utilizes higher doses and is approved on the NHS specifically for weight management
- Ozempic employs lower doses for treating type 2 diabetes
- Rybelsus is an oral medication with lower doses also used for type 2 diabetes
Researchers suggested that Rybelsus's lack of association with eye strokes might be attributed to "the limited absorption and slower uptake" of the oral formulation compared to injectable versions.
Regulatory Response and Manufacturer Position
Novo Nordisk, the pharmaceutical company producing all three medications, responded to the findings with a statement emphasizing patient safety. "We take any reports about adverse events from the use of our medicines very seriously," a company spokesperson said. "We work closely with authorities and regulatory bodies from around the world to continuously monitor the safety profile of our products."
The company has updated patient information leaflets for all three medications in the European Union to include warnings about non-arteritic anterior ischemic optic neuropathy (NAION), the specific type of eye stroke examined in the study. However, Novo Nordisk maintains that their internal data "did not suggest a reasonable possibility of a causal relationship between semaglutide and NAION" and believes "the benefit-risk profile of semaglutide remains favourable."
Urgent Calls for Further Investigation
The study authors emphasized the need for immediate follow-up research, stating: "These findings highlight a potential dose-dependent safety concern that warrants urgent prospective evaluation to guide prescribing and regulatory policy."
This warning comes as weight loss medications like Wegovy have gained significant popularity, with Wegovy specifically approved for NHS use to assist with weight management through higher-dose regimens. The research underscores the importance of continued monitoring and transparent communication about potential risks associated with pharmaceutical treatments, particularly as their usage expands across patient populations.
