Weight loss jabs 'may be needed for life', study says

People who take weight loss jabs may need to continue the medication for life, researchers have said, after a major study found they put all the weight back on four times faster than traditional dieters after stopping treatment.

Researchers from the University of Oxford discovered that people taking drugs including Wegovy and Mounjaro regained any weight lost within 20 months of stopping the jabs.

Improvements to blood sugar levels, cholesterol and blood pressure are also lost when people stop the drugs, with patients ending up back where they were at the start of their diet journey.

In contrast, people who are supported to lose weight through healthier diets and exercise keep the weight off for far longer – just under four years – though they do, on average, also regain it eventually.

At present, Wegovy can only be prescribed on the NHS for a maximum of two years. There is no limit on the amount of time patients can be prescribed Mounjaro.

The vast majority of people taking Wegovy and Mounjaro pay privately owing to restrictions on who can access the medicines via the NHS.

However, studies suggest half of people come off their weight loss medication, with reasons including no longer being able to afford jabs privately, side-effects or because they have reached a goal weight.

Susan Jebb, professor of diet and population health at the University of Oxford and adviser to ministers and the NHS on obesity, said: “In summary, what we’ve shown in this particular piece of analysis is that weight regain after medication is common and is rapid.

“The cardiometabolic benefits essentially parallel weight – and so as weight is regained, the cardiometabolic benefits are lost.

“It’s important to note that the rate of weight regain is almost four times faster than after behavioural programmes, and that’s regardless of the amount of weight loss during treatment.”

She suggested people may need a lifetime solution – such as obesity jabs or behaviour change support or both – to tackle obesity in the long-term.

She said “it’s very clear that some type of treatment, some sort of intervention, needs to continue” if the benefits of drugs for obesity are to last long-term.

Professor Jebb added that people paying privately for the drugs “need to be aware of the very high risk of rapid weight regain when treatment ends” so they can make decisions about long-term treatment “aware of the financial consequences”.

An NHS spokesman said: “While these new treatments are an important new tool for supporting weight loss, they’re not a magic fix and must be paired with behavioural and lifestyle wraparound support including advice on healthier diets and physical activity to keep the weight off in the long term.

“That’s why the NHS continues to implement innovative ways to support people to lose weight safely and sustainably as well as offering a range of weight management services, including the NHS Digital Weight Management Programme, which will be expanded to 125,000 more people per year as part of the 10-year health plan.”