Dani Alcedo, is an expert dietitian with over a decade of experience, including several years working for the NHS in the UK. He specialises in nutrition, diabetes, cholesterol and weight loss and makes bespoke dietary plans for his patients. (If you would like a consultation with Dani, contact him via email: alcedonutrition@gmail.com)

Britain’s medicines watchdog has strengthened its warnings over popular drugs such as Ozempic, Wegovy and Mounjaro after reports of a potentially life-threatening inflammation of the pancreas, including cases in which the organ’s tissue has begun to die.

The Medicines and Healthcare products Regulatory Agency (MHRA) announced the move on January 29, warning that acute pancreatitis is a recognised, albeit uncommon, side effect of GLP-1 medications.

Between 2007 and October 2025, the regulator received 1,296 reports of pancreatitis associated with GLP-1 and related GLP-1/GIP medicines in the UK. Some 19 reports involved a fatal outcome, while 24 concerned necrotising pancreatitis, a particularly severe form of the condition.

The figures are likely to raise fresh questions about the safety of medications that have transformed the weight-loss industry and become increasingly popular among people looking for a medical shortcut to a slimmer waistline.

But there is an important distinction, as these are reports of suspected adverse reactions, not proof that the drugs directly caused every case. The figures also do not establish the likelihood of an individual patient developing pancreatitis.

So what are the risks?

GLP-1 medicines work by mimicking hormones involved in appetite regulation and blood sugar control. They can help people feel fuller for longer, reduce appetite and, in some cases, achieve substantial weight loss.

Semaglutide, sold as Ozempic and Wegovy, and tirzepatide, marketed as Mounjaro, are among the best-known examples.

Their popularity has surged as weight-loss injections have moved from specialist diabetes treatment into mainstream conversations about obesity, celebrity culture and body image.

However, the MHRA says patients and healthcare professionals must remain alert to symptoms of acute pancreatitis, which can initially be mistaken for the nausea, vomiting and abdominal discomfort commonly associated with these medicines.

The warning covers GLP-1 receptor agonists including semaglutide, liraglutide and dulaglutide, as well as dual GLP-1/GIP medicines such as tirzepatide.

In rare cases, pancreatitis can become necrotising, meaning parts of the pancreas die. The regulator has also received reports of fatal cases.

The warning signs

The MHRA advises anyone taking these medications to seek urgent medical attention if they develop severe, persistent abdominal pain, particularly if it spreads towards the back or occurs alongside nausea and vomiting.

Patients should not simply assume that significant abdominal pain is another routine side effect of their injection.

Healthcare professionals have been advised to discontinue the medicine immediately if pancreatitis is suspected. If the diagnosis is confirmed, treatment should not be restarted.

The regulator also advises caution when prescribing these medicines to people with a history of pancreatitis.

Importantly, people obtaining weight-loss injections privately should tell medical professionals they are using them. Such prescriptions may not appear in their usual medical records.

Do the figures prove the jabs are causing pancreatitis?

Not necessarily.

The MHRA’s figures come from its Yellow Card reporting system, which collects suspected adverse drug reactions. Such reports are essential for identifying potential safety problems, but they cannot establish a definitive causal link or calculate the precise risk for someone taking a particular medication.

For context, the regulator estimates that approximately 25.4 million packs of GLP-1 medicines were dispensed in the UK over the five years covered by its prescribing data.

That is a substantial volume of medication, although comparing the number of packs with the number of reports does not provide a reliable estimate of an individual patient’s risk.

A separate BMJ rapid response published on January 30 also urged caution in interpreting the reports. It argued that gallstones associated with rapid weight loss could explain some cases of pancreatitis, rather than a direct toxic effect of the drugs on the pancreas.

Gallstones are a recognised cause of acute pancreatitis, and rapid weight loss can increase the risk of gallstone formation. GLP-1 medicines have also been associated with an increased risk of gallbladder and biliary disease.

This is a possible explanation, not a settled conclusion about the cause of the reported cases. The relationship between these medications and pancreatitis remains a safety issue requiring careful assessment.

Should patients stop taking their injections?

The strengthened warning does not mean everyone taking Ozempic, Wegovy or Mounjaro should stop treatment.

These medicines have established benefits for appropriately selected patients, and the MHRA continues to recognise their authorised uses. The key message is to understand the risks, use the medication under appropriate medical supervision and take warning symptoms seriously.

Anyone experiencing severe, persistent abdominal pain should seek urgent medical assessment. If pancreatitis is suspected, the MHRA says treatment should be discontinued immediately, with no restart if the diagnosis is confirmed.

Suspected side effects can also be reported through the UK’s Yellow Card scheme.

For a class of drugs increasingly marketed as a solution to one of modern society’s most visible health concerns, the latest warning is a reminder that powerful medicines are not cosmetic accessories.

The promise of losing weight may be appealing. The pancreas, however, does not care about the number on the scales.

A dietitian’s view

For dietitians, the latest warning highlights the importance of treating obesity as a complex, long-term health condition rather than simply a number on the scales.

‘GLP-1 medications can be effective tools for managing obesity and type 2 diabetes, but they are not risk-free, and they should never be treated as a quick cosmetic fix,’ is the message healthcare professionals should be communicating to patients.

From a dietetic perspective, weight loss is only one part of the picture. Nutritional adequacy, muscle preservation, hydration, gastrointestinal tolerance and long-term maintenance all matter, particularly when appetite is significantly suppressed.

Patients taking these medications may struggle to eat enough to meet their nutritional requirements. Dietetic support can help them prioritise protein, maintain a balanced diet and identify when reduced food intake is becoming a concern.

But the latest pancreatitis warning highlights a more immediate issue: patients must know which symptoms require urgent medical attention.

Severe, persistent abdominal pain should not be dismissed as an ordinary side effect of a weight-loss injection. Anyone experiencing such symptoms should seek urgent medical assessment, and treatment should be discontinued if pancreatitis is suspected, in line with MHRA advice.

The wider lesson is that medication and nutritional care should complement one another. Prescribing an injection without appropriate follow-up risks reducing obesity management to a prescription, rather than a comprehensive approach to health.

The objective should not simply be to help people lose weight, but to help them improve their health safely, sustainably and with the support they need.