‘King Kong’ of fat jabs Mounjaro will be free on NHS for millions after helping patients lose 24% of their body weight
Everything you need to know about new fat shedding medicines is explained in the video above
THE ‘King Kong’ of fat jabs will be available on the NHS, health chiefs announced today.
Mounjaro has already been rolled out to people with type 2 diabetes but will soon be given to those with severe obesity too.
The medicine, also called tirzepatide, works in a similar way to celebrity-endorsed Ozempic and Wegovy, which have been hailed as “miracle” off-label weight loss drugs.
Subject to final guidance, the once-weekly jab will be recommended for patients with a body mass index (BMI) of 35 or above – meaning it could be made available to millions of Brits.
Patients will also need to have at least one obesity-related condition, such as type 2 diabetes, to be eligible.
The drug will be prescribed alongside a reduced-calorie diet and exercise.
A lower BMI threshold – usually reduced by 2.5kg (5.5lb) – may be used for people from Asian, South Asian, Chinese, Middle Eastern, black African or African-Caribbean ethnic backgrounds.
Guidance from the National Institute for Health and Care Excellence (Nice) said manufacturer Eli Lilly proposes that the drug should be available to those with a BMI of 30 with at least one weight-related condition.
However, the spending watchdog said “most likely cost-effectiveness estimates for this group are above the range that Nice considers an acceptable use of NHS resources”.
Mounjaro would provide an alternative to Wegovy — or semaglutide — which has also been in short supply due to overwhelming demand.
Tirzepatide works by suppressing two appetite-regulating hormones, making people feel fuller for longer while also making them experience fewer food cravings.
Previous research found it helped people lose 24 per cent of their body weight.
The jab should be supplied in a four-dose pen, which provides a month’s treatment when used once a week, Nice said.
It was previously only available in single doses.
Reacting to the publication of the draft guidance, Sir Stephen O’Rahilly, of the Medical Research Council Metabolic Diseases Unit at the University of Cambridge, said drugs like Mounjaro “will become a central plank of how we help people living with obesity to live longer and healthier lives”.
He added: “Given the very positive recent results of large, randomised control trials with this drug and its beneficial effects on a range of outcomes, this decision is not surprising.
“We are clearly in a new era of obesity management where, for the first time, we can have access to medicines which are effective and, though not without some side-effects, largely safe.”
These drugs significantly reduce the risks of developing distressing and expensive complications
Sir Stephen O'Rahilly
The Nice recommendation on Mounjaro, hailed the “King Kong of fat jabs”, comes after Wegovy was given the green light to treat obesity on the NHS last year.
The drug was launched in the UK in August and is recommended for those with a BMI of 30, or between 27 and 30 in the presence of at least one obesity-related condition.
A four-week supply of pre-filled pen injections of Mounjaro ranges from £92 for the lowest dose to £122 for the highest.
The price of Wegovy ranges from £73.25 to £175.80 per pack, with each pack containing one pen that delivers four doses.
However, Wegovy manufacturer Novo Nordisk has a commercial arrangement which makes it available on the NHS at a discount.
It is understood there is no agreement in place for Mounjaro.
Prof Sir Stephen added: “This class of injectable drug is currently expensive, providing particular challenges to a taxpayer-funded health system like the NHS.
“In the longer term, these drugs significantly reduce the risks of developing distressing and expensive complications such as type 2 diabetes, heart attacks and kidney failure but their cost provides an immediate financial challenge at a time when NHS budgets are tight.”
Data from the Health Survey for England in 2020 estimates 1.4million people are morbidly obese, meaning they have a BMI of 40 or more.
Everything you need to know about fat jabs
What you should know about Ozempic, Wegovy, Saxenda and Mounjaro
Weight loss jabs are a hot media topic at the moment, with hundreds of success stories sharing how they helped them shed the pounds.
In March 2023, the NHS announced it would make Wegovy, a drug made by Danish firm Novo Nordisk, available on prescription to thousands of obese Brits.
It contains the drug semaglutide, which is said to have helped reality star Kim Kardashian and Twitter boss Elon Musk lose weight.
Wegovy, which helped a third of people reduce their weight by 20 per cent in trials, is now available from pharmacies like Boots.
How do they work?
The jabs work by suppressing your appetite, making you eat less calories and therefore lose weight.
To do this, an ingredient found in the fat-busting drug, known as Semaglutide, mimics the role of a natural hormone, called GLP-1.
GLP-1 is part of the signalling pathway that tells your body you have eaten, and prepares it to use the energy that comes from your food.
London GP and founder of , Dr Zoe Watson, said: “Your body naturally produces an appetite regulating hormone called glucagon-like peptide-1.
“These jabs work by regulating your appetite, which can lead to eating fewer calories and losing weight.”
Aren’t they diabetes drugs?
Semaglutide, the active drug in Wegovy, was originally sold under the name Ozempic specifically for diabetes patients.
But they started noticing it helped suppress their appetites, stopping them eating as much and helping them shed the pounds.
So Novo Nordisk developed Wegovy, which contains the same chemical but at higher doses specifically to aid weight loss.
Wegovy is not prescribed for diabetes patients.
Can I get them?
Wegovy is offered on prescription to obese adults given specialist weight loss treatment.
The NHS currently also offers a similar drug called Saxenda, or liraglutide.
Both are only available on Tier 3 and Tier 4 weight management services, which means you have to be referred to weight management clinics led by experts.
GPs can’t prescribe them on their own either, Dr Watson said.
The jabs have to be taken as part of an overall programme to help with lifestyle changes and psychological support to get the best effect from the medication prescribed.
But despite being approved for use, supply of Wegovy on the NHS has been postponed indefinitely because of a surge in worldwide demand.
Supply was also halved in the US because of the skyrocketing demand.
Are there any risks?
Like all medicines, the jabs do not come without side effects.
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, thyroid tumours, gallbladder problems and hypoglycemia.
What other options are there?
Mounjaro (brand name for tirzepatide) also came onto the market in early 2024.
Like Wegovy, tirzepatide stems from a drug originally designed to treat diabetes.
The weekly injection helped overweight people drop more than two stone in 18 months.
It is available with to order with a prescription online from pharmacies including Superdrug and LloydsPharmacy Online Doctor.
It works in a similar way to Wegovy and Saxenda, but is more effective.
Dr Mitra Dutt from says: “Based on clinical trials, 96 per cent of people were able to lose more than five per cent of their body fat using Mounjaro. In similar trials, 84 per cent of people lost more than five per cent of their body weight on Wegovy, and 60 per cent on Saxenda.
“Mounjaro works by activating two hormonal receptors (GIP and GLP-1), which enhance insulin production, improve insulin sensitivity, and work to decrease food intake.”