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The shock death of a teenage London student is the latest fatality in the UK linked to weight loss jabs like Wegovy and Mounjaro.

An inquest last week heard that Josephine Nasr suffered a deadly irregular heart rhythm in her dorm room at the University of East London, in September 2025

The 19-year-old, who was overweight but not obese, had been prescribed tirzepatide – the active ingredient in Mounjaro – in California, where she was born.

The coroner offered a conclusion that, on the balance of probabilities, the prescribed tirzepatide caused low blood sugar, which led to her developing an electrolyte imbalance.

Together with an underlying heart condition myocardial bridging, this is believed to have triggered an abnormal heart rhythm, cardiac arrhythmia, that ultimately resulted in her death.

It comes less than a week after a Daily Mail analysis found that weight-loss jabs have been linked to at least 216 deaths in Britain, 120 of whom had used tirzepatide.

The alarming reports may fuel concern among the estimated 2.5million Britons who use the jabs, known medically as GLP-1 agonists. But just how risky are they?

An empty vial of tirzepatide was discovered in Josephine Nasrdorm room, where she was found dead on September 23

The injections have been associated with benefits beyond shedding fat – sometimes up to four stone in a matter of months – including protecting against disease, diabetes, dementia and cancer.

But they also come with some serious side effects.

The Medicines and Healthcare products Regulatory Agency (MHRA) says common complications of taking GLP-1s include nausea, vomiting, diarrhoea and constipation.

While severe dehydration, related to vomiting, and allergic reactions can be very dangerous, another extreme side effect is severe acute pancreatitis, which can be deadly.

When the Daily Mail analysed reports made to the MHRA's Yellow Card scheme – the UK's system for tracking suspected adverse drug reactions – most of the 18,000 serious or fatal reactions linked to GLP-1s affected the gastrointestinal system, which includes acute pancreatitis.

It is unclear how many Yellow Card reports related specifically to pancreatitis, and previous studies – including one in 2025 – found that GLP-1 patients did not face a higher risk of developing it.

However, the MHRA updated its guidance in January relating to GLP-1 drugs to 'highlight the potential risk of severe acute pancreatitis with these products'.

Acute pancreatitis – when the pancreas suddenly becomes swollen and painful – is a rare but known complication of taking GLP-1s.

The patient information leaflet for popular jabs like Wegovy, Ozempic and Mounjaro includes a warning that acute pancreatitis may affect up to one in 100 patients.

The MHRA said that there was a 'small risk' of GLP-1 users developing severe acute pancreatitis, which can trigger life-threatening complications like multiple organ failure.

MHRA officials said they received 1,296 reports of pancreatitis, including acute, autoimmune, chronic, haemorrhagic, necrotising, subacute and obstructive forms, from 2007 to October 2025.

And 19 of those reports resulted in deaths, they said, which is around 1.5 per cent.

Twenty-four of the reports were classed as necrotising pancreatitis, which is a severe and life-threatening form where tissue in the pancreas and surrounding areas dies.

The MHRA stressed that these reports were made while 25.4 million packs of GLP-1 drugs were dispensed, showing that the risk remains small.

But the health chiefs said professionals should be 'alert to the risk of acute pancreatitis' for patients taking GLP-1s.

In their announcement, the body also said all GLP-1 patient information leaflets would be updated to 'highlight reports of necrotising pancreatitis and reports with a fatal outcome'.

It urged any patients with severe symptoms – which include sudden and intense stomach pain, as well as having a high temperature and feeling sick – to seek urgent medical care.

A 2017 study cited by the National Institute for Health and Care Excellence found that acute pancreatitis has around a 5 per cent fatality rate out of 400 people.

The NHS says: 'In severe cases where complications develop, there's a high risk of the condition being fatal.

'If a person survives the effects of severe acute pancreatitis, it's likely to be several weeks or months before they're well enough to leave hospital.'

Separately, experts say a range of other drugs may trigger acute pancreatitis – it's not just GLP-1s.

These include thiazides, which treat heart failure and high blood pressure, azathioprine, which suppresses the immune system and tetracyclines, used to manage bacterial infections.

Epilepsy drug sodium valproate has also been linked, as has frusemide – used to treat dangerous fluid build-up – as well as oestrogens in hormone replacement therapy (HRT), anti-inflammatory drugs corticosteroids and antibiotics sulphonamides.

A further potential risk of taking GLP-1s includes acute gallstone disease, occurring when gallstones – usually made of cholesterol – form in the gallbladder, which is an organ under the liver.

This can block the flow of bile, a fluid produced by the liver, and cause severe pain in the right side of the stomach.

Untreated, it can lead to dangerous infections in the nearby organs like the pancreas, liver and the stomach lining which can trigger high fever, shock and jaundice.

The NHS says most cases of gallstone disease are 'easily treated with surgery'.

But, they add: 'Very severe cases can be life-threatening, especially in people who are already in poor health. However, deaths from gallstone disease are rare in the UK.'

Experts have also warned that up to one in 100 GLP-1 users may also suffer allergic reactions, and up to one in 1,000 may also suffer severe allergic reactions, known as anaphylaxis.

Anaphylaxis is responsible for around 20 deaths per year in the UK, and is often extremely dangerous because its symptoms can come on very suddenly.

Patients should be aware of symptoms such as a redness or swelling at the point of GLP-1 injection, if patients are taking the jabs, as well as breathing difficulties, hives and facial swelling.

Officials have been keen to stress that most GLP-1 patients need not worry because dangerous symptoms are so rare, but they advised people should still remain vigilant.

Alison Cave, the MHRA's chief safety officer, said after the pancreatitis guidance was updated: 'For the vast majority of patients who are prescribed GLP-1s, they are safe and effective medicines which deliver significant health benefits.

'The risk of developing these severe side effects is very small, but it is important that patients and healthcare professionals are aware and alert to the associated symptoms.

'If you, or someone you care for, is taking GLP-1s and you notice symptoms such as severe, persistent stomach pain that may radiate to the back and may be accompanied by nausea and vomiting, then we advise you speak to a healthcare professional and report it via our Yellow Card scheme.'

Yellow Card reports can be submitted from members of the public, healthcare professionals and those who work in the pharmaceutical industry.

The MHRA stress that they do not prove that a medicine caused a reaction to happen, only that it is suspected by the individual making the report.

Other pre-existing health conditions, which many people taking GLP-1s already have, may explain some of the deaths reported from patients on the Yellow Card scheme.

The Daily Mail's analysis last week found that, on top of the 120 deaths linked to tirzepatide, semaglutide – sold under brand names Wegovy and Ozempic – was linked to 59.

Meanwhile, liraglutide, known as Saxenda, was associated with 37 fatalities.

A total of 150,000 adverse reactions were found to be associated with the drugs.

After the revelations, experts stressed that these findings do not mean the medications are inherently dangerous.

Naveed Sattar, a professor of cardiometabolic medicine and honorary consultant at the University of Glasgow, said: 'All medicines require ongoing monitoring, and regulators rightly continue to assess emerging safety signals.

'Reports of deaths in people taking weight loss medicines should be interpreted with caution and should not unnecessarily alarm the many people who are benefiting from these treatments.

'The people prescribed these medicines often already have conditions such as obesity, diabetes, high blood pressure, heart disease and kidney disease. These conditions themselves increase the risk of serious illness and premature death.

'As a result, when millions of individuals at higher risk take a medicine, some will inevitably experience major health events or die when on treatment, regardless of whether the medicine played any role.

'We do also know that because some individuals get these medicines privately those people won't all necessarily have significant health conditions unlike those that get the medicines via the NHS – it's important all those people report any problems to their doctors.'

Dr Marie Spreckley, a researcher in prevention of diabetes and related metabolic disorders in high risk groups at the University of Cambridge, added: 'Overall, the evidence continues to show that these medicines provide substantial health benefits for many people when prescribed appropriately, although, like all medicines, they can cause rare but serious adverse effects.

'Continued pharmacovigilance and careful patient monitoring definitely remain essential.'