New weight-loss jab side effect 'alarming and permanent', pharmacist says

A pharmacist with 30 years experience says she would never take weight loss drugs as 'alarming' side effects are coming to light. Drugs which were originally designed to control diabetes are now routinely used for weight loss, and by the start of the summer, 1.5million people in the UK were already using them.

But Deborah Grayson, who runs Digestion with Confidence, is concerned about the potentially permanent issues stemming from even short-term use of the jabs.

She said: "I’m seeing and hearing about a rise in patients suffering from serious, long-lasting gut issues caused by the very weight-loss injections that are supposed to help them. These conditions are life changing. These GLP-1 receptor agonists work by slowing the stomach to make people feel full faster. That’s why they’re so effective for weight loss, but for some, this effect can become a curse.

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"The condition I’m seeing more of is called gastroparesis - delayed gastric emptying - where the stomach can no longer move food along at a normal rate. Symptoms are relentless: people feel full after tiny amounts of food, experience nausea or vomiting, bloating, stomach pain and heartburn.

"While delayed gastric emptying is listed as an uncommon side effect (affecting one in 100 to one in 1000 patients), on the manufacturer’s data sheet for weight loss medication, permanent gastroparesis is not listed. What’s alarming is that, although we’ve always thought these issues would resolve when the injections are stopped, now we are discovering that this isn’t always the case, leaving many patients with permanent symptoms.

"This is not just uncomfortable; it’s life-altering. Eating becomes stressful, nutritional intake drops and in severe cases malnutrition can occur. Daily life - even enjoying a family meal - can turn into a constant battle against nausea and pain."

Only 14 per 100,000 people are diagnosed with gastroparesis in the UK and while it affects people of all ages, women are twice as likely to suffer from it and, according to the charity Guts UK, it’s most often diagnosed in people aged 18 to 39. The NHS urges sufferers to see a GP when they feel symptoms including feeling full quickly after eating, experiencing nausea or vomiting after eating, chronic stomach pain, constant heartburn for three weeks or more and bloating for three weeks or more, which could be signs of the condition.

Ms Grayson added: "What concerns me further is that these gut symptoms often lead to increased prescriptions of acid-reducing medications like proton pump inhibitors. These are one of the most prescribed medications in the UK, and long-term use has been linked to a number of conditions including dementia.

"Patients taking GLP-1s see their GPs complaining of heartburn or reflux-like discomfort, and the obvious response is to treat it with a PPI. While this can relieve some of the acid-related discomfort, it doesn’t address the underlying problem, which is delayed gastric emptying.

"In fact, taking PPI medication for gastroparesis can sometimes worsen symptoms rather than help, as it doesn’t address the underlying delayed stomach emptying and may contribute to further digestive issues. With GLP-1 medications being prescribed at higher doses to maximise weight loss, I predict we’ll see more people experiencing both persistent gastroparesis and reliance on PPIs.

"The irony is that a treatment intended to improve health can indirectly cause long-term gastrointestinal complications and additional medication use."

NHS advice for managing a gastroparesis diagnosis includes switching to four to six small meals a day, reducing the amount of indigestible insoluble fibre (found in wholegrain bread, beans and some vegetables and fruit) in your diet, and going on a liquid diet, eating soups or meals blended in a food processor.

Ms Grayson said: "I would urge patients and healthcare professionals to take this seriously. Anyone starting these injections should be fully aware of the potential for severe and, in some cases, permanent digestive issues. Doctors need to monitor symptoms closely and consider alternatives for people with a history of gastrointestinal problems. Patients experiencing persistent nausea, vomiting, bloating or early satiety should speak to their GP immediately.

"Early recognition may help manage symptoms before they become chronic. These medications have a place in treating obesity and diabetes, but the risks are real, and awareness is crucial. We cannot underestimate the impact permanent gastroparesis has on quality of life, and we must be vigilant to prevent this silent, debilitating side effect."

The drugs have also been linked to other serious side effects. Ms Grayson previously warned about an increase in people needing to have their gallbladders removed. Hundreds of people have reported problems with their pancreas linked to taking weight loss and diabetes jabs, prompting health officials to launch a new study into side effects.

Some cases of pancreatitis reported to be linked to GLP-1 medicines (glucagon-like peptide-1 receptor agonists) have been fatal. Data from the medicines regulator, the Medicines and Healthcare products Regulatory Agency (MHRA), shows that since the drugs were licensed there have been hundreds of cases of acute and chronic pancreatitis among people taking GLP-1 medicines.

This includes:

• 181 reported cases of acute and chronic pancreatitis linked to tirzepatide – the active ingredient for Mounjaro. Five people died.
• 116 reported reactions of this kind linked to liraglutide, one of which was fatal.
• 113 cases of acute and chronic pancreatitis linked to semaglutide – the active ingredient for Ozempic and Wegovy. One person died.
• 101 reported reactions of this kind linked to exenatide, three people died.
• 52 reported reactions of this sort linked to dulaglutide and 11 reported reactions lixisenatide. No fatalities were linked to either drug.

These cases are not confirmed as being caused by the medicines, but the person who reported them suspected they may be.

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