The UK medicines regulator has launched a probe into the safety of fat jabs after hundreds of Britons developed pancreatitis, leaving ten dead.

Officials are examining whether those affected have a genetic trait that leaves them at greater risk of side-effects from the likes of Mounjaro, Wegovy and Ozempic.

The Medicines and Healthcare products Regulatory Agency (MHRA) said it has received more than 560 reports of people developing an inflamed pancreas after taking so-called ‘GLP-1′ injections since they were first launched. Ten cases proved fatal.

These drugs are typically known as ‘fat jabs’ or ‘skinny jabs’ as they are frequently used for weight management, but some are primarily licensed for the treatment of type 2 diabetes.

The MHRA is now calling for users who are admitted to hospital with pancreatitis to report the side effect to authorities using the regulator’s Yellow Card scheme.

Healthcare workers can also submit a report on patients’ behalf.

When a Yellow Card report is received, the MHRA will contact patients to ask if they would be willing to take part in the new Biobank study, in collaboration with Genomics England.

This would involve providing further information and submitting a saliva sample which will be used to explore whether some people are at a higher risk of acute pancreatitis when taking these medicines due to their genetic makeup.

Susan McGowan, 58, from Lanarkshire, died from multiple organ failure, septic shock and pancreatitis last year after taking two low-dose injections of tirzepatide

Researchers hope this will ultimately enable doctors to use rapid genetic screening tests before prescribing drugs to make the process safer.

Side effects continue to be a significant burden on the NHS and studies have shown they account for one in six hospital admissions.

The main symptom of pancreatitis is severe pain in the stomach that radiates to the back and does not go away. Anyone who experiences this should seek immediate medical help.

Dr Alison Cave, MHRA’s chief safety officer, said: ‘Evidence shows that almost a third of side effects to medicines could be prevented with the introduction of genetic testing.

‘It is predicted that adverse drug reactions could cost the NHS more than £2.2 billion a year in hospital stays alone.

‘Information from the Yellow Card Biobank will help us to better predict those most at risk of adverse reactions—enabling patients across the UK to receive the safest medicine for them, based on their genetic makeup.

‘To help us help you, we’re asking anyone who has been hospitalised with acute pancreatitis while taking a GLP-1 medicine to report this to us via our Yellow Card scheme.

‘Even if you don’t meet the criteria for this phase of the Biobank study, information about your reaction to a medication is always extremely valuable in helping to improve patient safety.’

GLP-1 agonists can lower blood sugar levels in people living with type 2 diabetes and can also be prescribed to support some people with weight loss.

Recent estimates suggest that about 1.5 million people in the UK are taking weight loss jabs, many of which are bought privately due to NHS rationing.

Health officials have suggested that they can help to turn the tide on obesity, but have stressed they are not a silver bullet and do come with side effects.

Most side effects linked to the jabs are gastrointestinal including nausea, constipation and diarrhoea.

However, the medical regulator recently warned that Mounjaro may make the oral contraceptive pill less effective in some patients.

The MHRA said it has been notified of 181 cases of acute and chronic pancreatitis linked to tirzepatide—the active ingredient for Mounjaro. 

Of these, five people died.

There have been 116 reported reactions of this kind linked to liraglutide, one of which was fatal, and 113 cases of acute and chronic pancreatitis linked to semaglutide—the active ingredient for Ozempic and Wegovy, with one death.

Some 101 reported reactions of this kind are linked to exenatide, with three deaths, and 52 reported reactions of this sort linked to dulaglutide and 11 reported reactions to lixisenatide.

There were no reported fatalities from pancreatitis linked to the last two drugs.

There have been further reactions and deaths linked to other side-effects following the use of GLP-1 medicines.

The MHRA stresses that it has not been established that the jabs caused the illnesses, but that the patients themselves have reported them as side effects.

Professor Matt Brown, chief scientific officer of Genomics England, said: ‘GLP-1 medicines like Ozempic and Wegovy have been making headlines, but like all medicines there can be a risk of serious side effects.

‘We believe there is real potential to minimise these with many adverse reactions having a genetic cause.

‘This next step in our partnership with the MHRA will generate data and evidence for safer and more effective treatment through more personalised approaches to prescription, supporting a shift towards an increasingly prevention-focused healthcare system.’