Weight loss and diabetes jabs linked to potentially fatal side effect

Weight loss and diabetes jabs taken by more than a million people in the UK have been linked to a potential serious side effect, with some deaths, according to data from the UK medicines regulator.

New figures from the Medicines and Healthcare products Regulatory Agency (MHRA) show the group of drugs that includes Mounjaro, Wegovy, and Ozempic may be associated with inflammation of the pancreas.

According to the MHRA, there have been 181 reported cases of acute or chronic pancreatitis linked to Mounjaro, with five deaths.

Wegovy and Ozempic have been linked with 113 reports of pancreatitis and one death.

Other, less widely used versions of so-called GLP-1 drugs have also been linked to cases and deaths.

There is no evidence that the drugs directly caused the deaths. And the evidence isn't strong enough for the MHRA to restrict access.

That's because pancreatitis also occurs in people who aren't taking the GLP-1 drugs, with about 560 cases for every one million people in the general population. Gallstones and alcohol are the biggest causes.

But the MHRA and Genomics England are launching a new study to see whether some people have genes that put them at higher risk of developing pancreatitis if they take GLP-1 drugs.

People reported through the MHRA's 'yellow card' alert system to have pancreatitis while using the jabs will be asked to provide a saliva sample and their genes tested.

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."

The main symptoms of pancreatitis are severe pain in the centre of the tummy area, fever and nausea. Acute cases are treated in hospital with fluids and oxygen, and generally make a recovery within a few days.

But there can be complications, and around 5% of acute cases are fatal.

With all medicines, there is a balance of risk and benefit.

For people with type 2 diabetes or obesity, there are clear benefits to using the jabs.

They lower blood sugar levels, lead to rapid weight loss and reduce deaths from cardiovascular disease by a fifth.

Read more:
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But for people who are a bit overweight and have sourced the jabs privately to lose a few pounds ahead of their summer holiday, the health benefits are far less clear.

This is a wake-up call for them.

These are powerful medications with effects not just on appetite, but on lots of body organs, including the brain.

And pancreatitis is just one of many possible side effects.

Lilly, the UK manufacturer of Mounjaro, has said patient safety is its "top priority".

The drug's patient information leaflet "warns that inflamed pancreas (acute pancreatitis) is an uncommon side effect (which may affect up to 1 in 100 people)," the statement continued.

Lily "also advises patients to talk to their doctor or other healthcare professional before using Mounjaro if they have ever had pancreatitis," it added.

Similarly, Novo Nordisk UK, which manufactures Wegovy and Ozempic, said in a statement: "Patient safety is of the utmost importance to Novo Nordisk.

"Like all medications, side effects can occur and vary from patient to patient. The known risks and benefits of GLP1 medicines are described in the Summary of Product Characteristics.

"We recommend that patients take these medications only for their approved indications and under the strict supervision of a healthcare professional, who can also advise on potential side effects."

(c) Sky News 2025: Weight loss and diabetes jabs linked to potentially fatal side effect