Tirzepatide: what is weight loss injection Mounjaro, what have the experts said - how is different to Ozempic?

• Nearly 250,000 people in England could access a weight loss injection on the NHS.
• Tirzepatide is prescribed for type 2 diabetes, but has been shown in clinical trials to be effective for weight loss.
• According to the Health Survey for England 2022, around 64% of adults are either overweight or obese.

Nearly 250,000 people in England could access the weight loss injection tirzepatide on the NHS under proposed plans.

The injection, known as Mounjaro and made by Eli Lilly, is used to treat type 2 diabetes and has been shown in clinical trials to be more effective in weight loss than diet and exercise support alone.

Plans to roll out the jab follow on from draft recommendations made by NICE in June, which stated that GPs would be allowed to prescribe the drug if supporting services were in place. The Health Survey for England 2022, found that around 64% of adults are either overweight or living with obesity in England, with obesity being the second most common cause of preventable death after smoking.

Speaking about the plans, Dr Sam Roberts, chief executive of NICE said: “This drug will be a powerful part of our arsenal to tackle obesity and support many more people to lose weight and reduce their risk of diabetes, heart attack and stroke, and this phased rollout will ensure those with the greatest clinical need can access it as a priority – with a quarter of a million people able to benefit over the first three years – while we develop new and innovative services through which other weight loss treatments can also be delivered.” 

Dr Roberts added: “With the sheer number of people potentially eligible for these treatments and GP teams already delivering record numbers of appointments, the NHS is developing a range of community-based and digital services to provide the benefits of weight loss drugs while continuing to ensure GPs can deliver all other vital services patients rely on.”

What is Tirzepatide?

Mounjaro, the brand name for tirzepatide, is a drug that treats type 2 diabetes by lowering blood sugar levels. According to Diabetes UK, it works by activating two receptors called GLP-1 and GIP to increase the level of hormones in the body.

Tirzepatide has also been recommended as a weight loss drug for adults, with proposals for the phased launch of it on the NHS being set out by NICE.

Who could be offered Tirzepatide?

Under the proposed plans outlined by NICE, to be eligible to receive the drug first, patients would need to have BMI over 40 and at least three specified weight-related health problems: hypertension, dyslipidaemia, obstructive sleep apnoea, or cardiovascular disease.

It would then be offered to patients with a BMI over 40 and two weight-related health problems and then to those with a BMI of over 40 and one weight-related health problem.

The weight loss injections will be offered as part of a package that also includes diet and exercise support.

What are the experts saying?

Reacting to the proposals Dr Simon Cork, Senior Lecturer in Physiology, Anglia Ruskin University (ARU), said: “The planned roll out of tirzepatide marks a key milestone in the future of obesity treatment. Like semaglutide (Ozempic, Wegovy), tirzepatide has been shown to be highly effective in clinical trials.”

Dr Cork explained: “The detail of what this roll out will look like is key to how effective this drug will be in a real-world setting. The NICE press release speaks of ‘community-based services’ and ‘digital technologies’ to roll out the medication to a ‘quarter of a million people’ with a multi-disciplinary team involved to provide dietary and nutritional support.”

He continued: “This is no small task for the NHS, and it will be difficult to provide the level of wraparound care seen in patients who took part in the clinical trial, and which is likely necessary to achieve maximum health benefits. We know for example that patients on weight loss drugs lose muscle mass as well as fat mass, and this loss of muscle has the potential to lead to frailty. Providing the right kind of exercise support is vital to ensure patients remain healthy on their weight loss journey.”

Adding: “Providing targeted and personalised dietary advice is also key to ensure that patient adherence to these drugs remains high and to maximise the amount of weight loss achieved. Without this high level of wraparound care, the NHS risks wasting money on these medications by not achieving the highest levels of weight loss possible. It is not clear whether the NHS has the capacity to provide this high level of wraparound care in the community to achieve this.”

How is it different to Ozempic?

Mounjaro, the brand name for tirzepatide, is a drug that is used to treat type 2 diabetes by lowering blood sugar levels. It is approved for weight loss in the UK, however Ozempic isn’t licensed as a weight loss treatment and is only licensed as a medicine for type 2 diabetes, but is sometimes prescribed for weight loss off-label.

Although similar to Ozempic, WebMD explains that the difference between the two is that tirzepatide acts on both the GLP-1 hormone and another metabolic hormone called GIP, whilst Ozempic only acts on GLP-1.

Some studies suggested that because of this, tirzepatide may be more effective for weight loss, with one study stating that a weekly 15mg dose led to people losing more than 20% of their body weight, compared to Ozempic’s 15-20%.

You can find ideas, tips and support on how live a healthier lifestyle from diet to exercise on NHS.UK.

Note: This article has been updated to make it clear that Ozempic is not licensed as a weight-loss treatment in the UK.