Popular weight loss injections including Ozempic, Wegovy and Mounjaro are facing renewed safety scrutiny after UK health authorities launched an investigation into potential links to life-threatening pancreatic inflammation.
The Medicines and Healthcare products Regulatory Agency (MHRA) has partnered with Genomics England to examine whether genetic factors may predispose some patients to developing acute pancreatitis while using the medications.
The study comes after hundreds of adverse event reports were filed through the UK’s Yellow Card safety monitoring scheme, including 10 cases where patients died after developing pancreatic complications.
“While these medicines have proven benefits, we must better understand and predict who might be at risk of serious side effects,” said Dr Alison Cave, the MHRA’s chief safety officer.
“This research could help identify vulnerable patients before they start treatment.”
The injectable drugs – known as GLP-1 receptor agonists – were originally developed to treat type 2 diabetes but have gained global popularity for weight loss. NHS prescriptions have surged alongside growing private sector demand, with many patients reportedly obtaining the medications through online pharmacies without proper medical oversight.
Medical experts say that while the drugs can produce significant weight reduction, they are not without risks.
Common side effects include nausea, vomiting and diarrhoea, but more concerning are reports of acute pancreatitis – a painful and potentially fatal inflammation of the pancreas requiring hospital treatment.
The new study will analyze genetic samples from affected patients to determine if certain DNA markers increase susceptibility to pancreatic complications. Researchers will also examine whether the medications might reduce the effectiveness of oral contraceptives, as suggested by preliminary MHRA warnings about Mounjaro.
Professor Rachel Batterham, an obesity specialist at University College London, cautioned:
“These are powerful medications that require careful monitoring. They should only be used as part of comprehensive weight management programme under medical supervision.”
Clinical trials have shown the injections can help patients lose 15-20% of their body weight, potentially reducing obesity-related health risks. However, the long-term effects remain unknown, and improper use – particularly through unregulated online sources – may be exacerbating safety issues.
Patients who have experienced adverse reactions are being encouraged to report through the Yellow Card scheme, with some invited to provide genetic samples for analysis.
Health officials stress that current users should not stop medication without consulting their doctor, but should seek immediate medical attention if they experience severe abdominal pain – a potential warning sign of pancreatitis.
