British health authorities have initiated a nationwide investigation into GLP-1 receptor agonists, including Ozempic and Mounjaro, following nearly 400 reports of acute pancreatitis linked to these medications. The Medicines and Healthcare products Regulatory Agency (MHRA) confirmed at least 10 fatalities among these cases, with tirzepatide-based Mounjaro accounting for almost half of all incidents reported in 2025 alone.
Genomics England has partnered with MHRA to establish the Yellow Card Biobank programme, a pioneering genetic analysis initiative targeting patients who developed pancreatic complications after using obesity treatments. The scheme builds on evidence suggesting 30% of adverse drug reactions could be prevented through pharmacogenetic testing – a critical consideration given that drug-related hospitalisations currently cost the NHS £2.2 billion annually. Professor Matt Brown, Chief Scientific Officer at Genomics England, emphasised that many severe side effects demonstrate hereditary patterns which could enable personalised prescribing.
Acute pancreatitis presents with severe epigastric pain radiating to the back, accompanied by nausea and fever. While drug manufacturers list this as an uncommon side effect, hospital admissions have risen sharply alongside prescription rates. MHRA safety director Dr Alison Cave confirmed surveillance systems detected disproportionate reporting frequencies, prompting the regulatory review. The agency maintains no conclusive evidence yet proves causation but acknowledges the temporal association warrants scrutiny.
Eligible participants – adults hospitalised for pancreatitis following GLP-1 therapy – can contribute saliva samples for whole genome sequencing. Clinicians are urged to report cases via the Yellow Card scheme, with the biobank aiming to identify high-risk genetic profiles. This comes amid unprecedented demand for weight-loss medications, with NHS England issuing 1.2 million GLP-1 prescriptions last quarter – a 240% increase from 2023 levels.
Parallel data from bariatric surgery registries show gastric procedures yield fivefold greater weight reduction than pharmacotherapy after two years. However, with 64% of UK adults now clinically overweight, health services face mounting pressure to expand treatment options. The investigation’s outcomes could reshape prescribing guidelines, particularly for patients with predisposing factors like metabolic syndrome or familial pancreatitis history.
MHRA continues monitoring other potential risks including intestinal obstruction and suicidal ideation, though current evidence remains inconclusive. Patients are advised not to discontinue medication without medical consultation but to seek immediate care if experiencing severe abdominal symptoms. The interim findings will undergo peer review by Q1 2026, with potential implications for global regulatory practices.
