The number of deaths linked to popular weight loss injections in the UK has risen to 216, with fatalities surging 300% in the past year. Government figures also indicate a significant increase in severe adverse reactions associated with these medications, such as Mounjaro and Wegovy.
Analysis of official drug safety data reveals that since 2010, approximately 150,000 adverse reactions have been reported in relation to these drugs, with 18,000 deemed serious or fatal. Gastrointestinal issues, including pancreatitis and gastroparesis (stomach paralysis), are among the most frequently reported severe side effects.
Tirzepatide and Fatalities
Tirzepatide, the active ingredient in Mounjaro, is associated with the majority of reported deaths. Since its licensing in the UK in 2024, 120 fatalities have been linked to this drug. For semaglutide, marketed as Wegovy and Ozempic, 59 deaths have been reported, and liraglutide (Saxenda) is linked to 37 fatalities.
Of the 18,000 serious or fatal reactions, 11,500 were specifically linked to tirzepatide. Close to 8,000 of these Mounjaro-related reports involved women. The drug manufacturer Eli Lilly stated that patient safety is a top priority and that they actively monitor and report safety information.
A Case of Perforation
Recent reports include the death of Caroline Savage, a 73-year-old grandmother, who died after increasing her Mounjaro dose. An inquest heard her death was due to faecal peritonitis, a life-threatening condition where bacteria leak into the abdomen through a hole in the bowel.
Experts suggest that weight loss injections, which are GLP-1 agonists mimicking appetite-suppressing hormones, may increase pressure in the intestines for individuals with certain underlying conditions. This increased pressure could raise the risk of bowel perforation. Penny Ward, a pharmaceutical expert from King's College London, explained that while nausea and vomiting are common, severe, sudden abdominal pain warrants investigation as it could indicate a perforation.
Regulatory Oversight and Manufacturer Statements
The figures were compiled from Yellow Card reports submitted to the UK's Medicines and Healthcare products Regulatory Agency (MHRA). These reports track suspected adverse drug reactions and can be made by the public, healthcare professionals, and pharmaceutical industry employees. Officials emphasize that these reports indicate suspicion rather than definitive proof of causation, as other health factors may be involved.
An MHRA spokesperson stated that the safety of GLP-1 receptor agonists is under continuous review, including emerging evidence from data and publications. The agency maintains that, based on current evidence, the benefits of these drugs outweigh the potential risks when used as authorized.
Novo Nordisk, the manufacturer of Wegovy, Ozempic, and Saxenda, acknowledged that like all medicines, these treatments can have side effects that vary among individuals and recommended reporting any experienced side effects to healthcare providers and the MHRA.
Eli Lilly encouraged patients to consult their doctors about any side effects and to ensure they are receiving genuine medication. NHS England declined to provide figures on hospitalizations related to GLP-1 users.