Weight-loss jab users warned to be 'aware and alert' as fatal new side effects revealed
Health officials around the world have issued a new warning to anyone taking weight loss jabs, after the weekly injectables were linked to a deadly new side effect.
According to new studies, GLP-1 medications - which include brands such as Mounjaro, Wegovy and Ozempic - pose a 'small risk' of a pancreas condition that could be life-threatening in some circumstances.
Though first rolled out to tackle the symptoms of type 2 diabetes, these GLP-1 medications have soared in sales in recent years, after a horde of Hollywood stars credited them as weight loss 'hacks'.
They work by mimicking certain hormones within the brain and regulating blood sugar and energy balance levels, both of which help to reduce a person's appetite and keep their cravings at bay.
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Since then, these injectables have continued to sky-rocket in both popularity and accessibility, with a handful now available on the NHS.
The most commonly reported side effects that you can expect to encounter while on weight loss jabs include nausea, constipation, diarrhoea, stomach discomfort and heartburn.
Being a relatively new medical marvel, however, researchers are still stumbling across new long-term side effects. This week, it was ruled that using GLP-1 medications could increase a person's risk of developing acute pancreatitis later down the line.
Experts have long postulated the possible impact that these medicines could have on the pancreas.
Between 2007 and October 2025, the MHRA has received 1,296 complaints of pancreatitis linked to GLP-1 drugs, with 19 having resulted in death.
As a reminder, it might be small in size, but the pancreas helps a person digest their food. It also plays a vital role in controlling their blood sugar and insulin levels - both processes which are impacted by these medications.
It is understood that this organ can become inflamed as a result of weight loss drugs, which could see it damaged, or stop working for good.
The warning was also issued alongside a series of indicators to look out for that the pancreas is under stress - like an extreme, relentless pain in the stomach and back areas, which could occur alongside nausea and vomiting.
Though pancreatitis can usually be treated in hospital with fluids, oxygen and antibiotics - failure to treat the infection can prove fatal.
"For the vast majority of patients who are prescribed GLP-1s, they are safe and effective medicines which deliver significant health benefits," MHRA’s chief safety officer Dr Alison Cave explained this week.
"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."
Eli Lilly, the firm that manufactures Mounjaro, previously told press of the pancreatitis risk: "Patient safety is Lilly’s top priority. We take reports regarding patient safety seriously and actively monitor, evaluate, and report safety information for all our medicines.
"Adverse events should be reported under the MHRA’s Yellow Card scheme, but may be caused by other factors, including pre-existing conditions. The Mounjaro (tirzepatide) Patient Information Leaflet warns that inflamed pancreas (acute pancreatitis) is an uncommon side effect (which may affect up to 1 in 100 people).
"It also advises patients to talk to their doctor or other healthcare professional before using Mounjaro if they have ever had pancreatitis. We encourage patients to consult their doctor or other healthcare professional regarding any side effects they may be experiencing and to ensure that they are getting genuine Lilly medicine."
A Novo Nordisk spokesperson - the brand that manufactures Wegovy and Ozempic - also previously told Tyla: "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.
"We continuously collect safety data on our marketed GLP-1 medicines and work closely with the authorities to ensure patient safety.
"The benefit-risk profile of our GLP-1 medicines remains positive, and we welcome any new research that will improve our understanding of treatments for people living with chronic diseases.”
Topics: Mounjaro, Health, Life, Real Life, True Life, Wegovy
Rhianna Benson