UK Health Officials Issue Urgent Warning Over Weight Loss Jabs and Vision Loss
The Medicines and Healthcare products Regulatory Agency (MHRA) has issued a stark warning about potential permanent vision loss associated with popular weight loss injections like Wegovy. This development follows growing concerns about a rare but serious complication that could leave patients with irreversible eye damage.
The 'Eye Stroke' Complication
Health officials have highlighted the risk of non-arteritic anterior ischemic optic neuropathy (NAION), often described as an 'eye stroke'. This condition occurs when arteries supplying blood to the optic nerve become blocked, potentially leading to permanent vision impairment. The complication was first formally reported in 2024 by researchers who identified the link between semaglutide-based medications and this serious eye condition.
The MHRA has now officially acknowledged this risk after previously maintaining that blindness was not a known adverse reaction to these medications. This represents a significant shift in official guidance regarding the safety profile of these widely prescribed drugs.
Immediate Action Required for Patients
In a strongly worded statement, the government organisation has urged all patients taking semaglutide medications to seek immediate medical attention if they notice any sudden changes in their vision. The warning specifically applies to those experiencing:
- Sudden impairment to their vision
- Rapid deterioration of eyesight in one or both eyes
- Any other concerning visual changes
Dr Alison Cave, MHRA's Chief Safety Officer, emphasised: '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.'
Updated Safety Guidance and Prescription Warnings
The regulatory body has implemented several important changes in response to these findings:
- All Wegovy prescriptions will now include specific safety warnings about the risk of blindness
- Healthcare professionals have been instructed to remain vigilant and specifically enquire about semaglutide use when patients present with vision problems
- Updated guidance has been issued to both medical practitioners and patients about recognising symptoms
This last point is particularly crucial because privately prescribed semaglutide, whether for weight loss or diabetes management, may not automatically appear on patients' medical records, potentially delaying diagnosis.
Scale of the Issue and Historical Data
Since semaglutide was first authorised in the UK in 2018, the MHRA has received just three suspected reports of NAION. However, this must be considered against the backdrop of approximately 10.2 million prescriptions issued over the past five years, highlighting both the medication's popularity and the rarity of this particular complication.
The condition itself affects around one in 10,000 people generally, and there are currently no established treatments available. Vision loss from NAION often does not improve, making early detection and intervention critically important.
Broader Investigation and Celebrity Concerns
The MHRA has announced it is now reviewing whether Mounjaro (tirzepatide), the other major weight loss jab available in the UK market, could pose similar risks. This expanded investigation follows concerns raised by high-profile figures including singer Robbie Williams, who publicly expressed fears last year that Mounjaro was affecting his vision.
The former Take That star reported increasingly blurry eyesight to the point where he struggled to see faces during live performances, ultimately requiring prescription glasses. His experience mirrors findings from previous studies published in JAMA Ophthalmology, which detailed cases of nine Canadian adults taking either semaglutide or tirzepatide who developed vision problems, with seven receiving NAION diagnoses.
Manufacturer Response and Legal Challenges
Novo Nordisk, the pharmaceutical company behind Wegovy and Ozempic (the diabetes version of semaglutide), maintains its position that blindness is not a known adverse drug reaction. However, the company is currently facing several lawsuits in the United States from patients who claim the medication has caused them to lose their sight.
Eli Lilly, manufacturer of Mounjaro, has also been approached for comment regarding the MHRA's expanded investigation into potential vision risks associated with their product.
Context of Widespread Use and Treatment Considerations
This warning comes at a time when approximately 2.5 million people in the UK are estimated to be using GLP-1 drugs like semaglutide and tirzepatide. These medications have revolutionised obesity treatment, offering weight loss results that were previously difficult to achieve through diet and exercise alone.
Current NHS guidelines restrict these drugs to patients with a BMI over 35 who have weight-related health conditions, or those with a BMI between 30 and 34.9 who are referred to specialist services. A recent landmark study has suggested that users may need to remain on these medications indefinitely to maintain weight loss, potentially exposing millions to long-term risks.
While these drugs can cause side effects including nausea, vomiting, and diarrhoea, and have been rarely linked to pancreatitis, medical experts generally maintain that the benefits outweigh the risks for most patients. However, the new vision loss warning adds another important consideration to the risk-benefit analysis that both patients and healthcare providers must now carefully evaluate.
