**Hundreds of Adverse Reactions and Multiple Deaths Spark Weight-Loss Injection Safety Study**
A growing number of adverse reactions and several deaths believed to be linked to popular weight-loss injections have prompted urgent investigations by UK health authorities. The Medicines and Healthcare products Regulatory Agency (MHRA) has highlighted mounting concerns over the safety of GLP-1 (glucagon-like peptide-1 receptor agonists) medicines after receiving numerous reports of pancreatitis and other complications associated with their use.
GLP-1 drugs, which include well-known names such as Ozempic, Wegovy, and Mounjaro, are widely prescribed for managing type 2 diabetes and, increasingly, for supporting weight loss efforts. However, new data reveals a concerning pattern. Since their introduction, the MHRA has documented several hundred cases of acute and chronic pancreatitis among people using these medications, with some cases proving fatal.
According to figures released by the regulator, reactions vary among the different GLP-1 drugs. Tirzepatide, the active ingredient in Mounjaro, is linked to 181 reports of pancreatic inflammation, including five deaths. Liraglutide has seen 116 similar reports, one of which was fatal. Meanwhile, 113 cases involving semaglutide—the compound found in both Ozempic and Wegovy—have included one fatality. Exenatide has been associated with 101 reports and three deaths, while dulaglutide and lixisenatide had 52 and 11 cases respectively, with no recorded fatalities from these drugs so far.
It is important to note that these cases are not yet confirmed as directly caused by the medicines themselves. Often, reports are made by patients or healthcare providers who suspect a possible connection. However, in response to these alerts, the MHRA, in partnership with Genomics England, has launched the Yellow Card Biobank project, an ambitious study designed to uncover potential genetic factors that could predispose individuals to such side effects.
The regulator is now appealing for individuals who have been hospitalised with acute pancreatitis whilst taking GLP-1 drugs to report their experiences via the Yellow Card scheme. If patients come forward, the MHRA may request additional information and a saliva sample, with the aim of determining whether certain genetic profiles may increase the risk of severe reactions to these treatments.
GLP-1 agonists have transformed the landscape of diabetes and obesity management for many, offering significant improvements in blood sugar control and weight loss. Recent estimates suggest as many as 1.5 million people in the UK are currently using weight-loss injections. Health officials maintain that while these drugs can be a powerful tool in addressing the obesity crisis, they are not a panacea, and their use does carry notable risks.
The most frequently reported side effects of these injections are gastrointestinal, such as nausea, constipation, and diarrhoea. Additionally, regulatory bodies have recently cautioned that Mounjaro may reduce the effectiveness of oral contraceptive pills in some users. As scrutiny intensifies, medical experts underscore the need for careful monitoring and informed decision-making by patients and practitioners alike.
Dr Alison Cave, the MHRA’s chief safety officer, has emphasised the significance of genetic testing in medication safety, citing that almost a third of all side effects could potentially be avoided. With adverse drug reactions estimated to cost the NHS more than £2.2 billion annually in hospital stays, there is considerable impetus to improve individual risk prediction. Dr Cave encouraged anyone affected to submit a Yellow Card report, stating, “With your help, we can better tailor medicines and protect patient well-being across the UK.”
Professor Matt Brown, chief scientific officer at Genomics England, echoed these sentiments, noting that while drugs like Ozempic and Wegovy have received widespread attention, their potential for serious side effects should not be overlooked. Brown expressed hope that genetic research could pave the way for more personalised and therefore safer prescription practices, contributing to a more preventative approach to healthcare.
As the investigation unfolds, the situation underscores the complex balance between the promise of medical innovation and the ongoing need for vigilance regarding safety and side effects. With genetic research at the forefront, authorities and patients alike are aiming for a future where treatments are as safe as they are effective—tailored to minimise risk and maximise benefit for all.