SO-CALLED “miracle” weight-loss jabs are far less effective in the real world than in clinical trials, a major study has revealed.
The new findings could have big implications for Brits considering the injections, which have soared in popularity across the UK in recent years.
AlamyIn a ‘real-world’ setting people might lose less weight in a regular clinical setting than during clinical trials[/caption] ReutersThe drugs work best when people stick to them and take the full recommended dose[/caption]Until now, the jabs have been hailed as an easier alternative to classic weight loss methods like calorie counting, weight watchers and the gym.
But researchers at the Cleveland Clinic in the US found average weight loss on the jabs in the ‘real world’ is just 6.9 per cent after a year.
This is less than half the amount typically seen in clinical trials, where patients often lose 15 per cent with semaglutide, the ingredient in Wegovy, and up to 22.5 per cent with tirzepatide, found in Mounjaro.
The study, published on Tuesday in Obesity, followed 7,881 adults with severe obesity who started semaglutide or tirzepatide between 2021 and 2023.
It discovered the drugs worked best when people stuck to them and took the full recommended dose, but in the real world, that rarely happened.
More than one in five patients (21 per cent) stopped taking the jabs within the first three months, and another 32 per cent quit between three and 12 months.
Meanwhile, over 80 per cent were on lower-than-recommended maintenance doses, needed to keep the weight off.
Those who quit early lost just 3.6 per cent of their body weight.
Patients who stayed on the treatment for a full year lost 11.9 per cent on average.
The best results were seen in people who stayed on full doses, who lost 13.7 per cent with semaglutide and 18 per cent with tirzepatide.
“Our findings could inform the decisions of healthcare providers and their patients on the role of treatment discontinuation and maintenance dosage in achieving clinically meaningful weight reductions,” Dr Hamlet Gasoyan, lead author of the study, said.
Among the 1,320 people with prediabetes, the precursor to type 2 diabetes, at the start of the study, those who stayed on the jabs were also far more likely to reverse the condition.
Don’t stop the drugs early
These medications work by copying a natural hormone found in the body called GLP-1.
This hormone helps people feel fuller for longer, which reduces appetite and helps with weight loss.
It also helps control blood sugar by telling the pancreas to make more insulin and slowing down how quickly sugar from food gets into the bloodstream.
That’s why these drugs are effective at both preventing type 2 diabetes and helping people shed pounds.
Just 33 per cent of early quitters returned to normal blood sugar levels, compared with 68 per cent of those who stayed on the medication.
“Type 2 diabetes is one of the most common complications of obesity, so diabetes prevention is very important,” Dr Gasoyan said.
“This study highlights that treatment discontinuation, especially early, negatively affects both weight and glycemic control outcomes.”
The most common reasons for stopping the jabs were cost, insurance issues, side effects and shortages, it said,
The experts said a follow-up study is planned to dig deeper into why patients quit, and what happens to their weight afterwards.
Everything you need to know about fat jabs
Weight loss jabs are all the rage as studies and patient stories reveal they help people shed flab at almost unbelievable rates, as well as appearing to reduce the risk of serious diseases.
Wegovy – a modified version of type 2 diabetes drug Ozempic – and Mounjaro are the leading weight loss injections used in the UK.
Wegovy, real name semaglutide, has been used on the NHS for years while Mounjaro (tirzepatide) is a newer and more powerful addition to the market.
Mounjaro accounts for most private prescriptions for weight loss and is set to join Wegovy as an NHS staple this year.
How do they work?
The jabs work by suppressing your appetite, making you eat less so your body burns fat for energy instead and you lose weight.
They do this my mimicking a hormone called GLP-1, which signals to the brain when the stomach is full, so the drugs are officially called GLP-1 receptor agonists.
They slow down digestion and increase insulin production, lowering blood sugar, which is why they were first developed to treat type 2 diabetes in which patients’ sugar levels are too high.
Can I get them?
NHS prescriptions of weight loss drugs, mainly Wegovy and an older version called Saxenda (chemical name liraglutide), are controlled through specialist weight loss clinics.
Typically a patient will have to have a body mass index (BMI) of 30 or higher, classifying them as medically obese, and also have a weight-related health condition such as high blood pressure.
GPs generally do not prescribe the drugs for weight loss.
Private prescribers offer the jabs, most commonly Mounjaro, to anyone who is obese (BMI of 30+) or overweight (BMI 25-30) with a weight-related health risk.
Private pharmacies have been rapped for handing them out too easily and video calls or face-to-face appointments are now mandatory to check a patient is being truthful about their size and health.
Are there any risks?
Yes – side effects are common but most are relatively mild.
Around half of people taking the drug experience gut issues, including sickness, bloating, acid reflux, constipation and diarrhoea.
Dr Sarah Jarvis, GP and clinical consultant at patient.info, said: “One of the more uncommon side effects is severe acute pancreatitis, which is extremely painful and happens to one in 500 people.”
Other uncommon side effects include altered taste, kidney problems, allergic reactions, gallbladder problems and hypoglycemia.
Evidence has so far been inconclusive about whether the injections are damaging to patients’ mental health.
Figures obtained by The Sun show that, up to January 2025, 85 patient deaths in the UK were suspected to be linked to the medicines.
Read More Details
Finally We wish PressBee provided you with enough information of ( Huge U turn as ‘impressive’ fat jabs proved to be LESS good at shedding pounds than we thought )
Also on site :