A daily pill could help people keep weight off after stopping weight-loss jabs, according to new research.
Trials found that patients given the tablet, called orforglipron, every day for a year avoided regaining much of the weight they had lost after coming off GLP-1 injections.
The drug is already available in the US and could soon launch in the UK.
The study, published in Nature Medicine, was funded by Eli Lilly, which also makes the weight-loss jab Mounjaro.
More research is needed to find out how long someone might need to stay on treatment. Experts say it might even need to be lifelong.
Dr Marie Spreckley, an expert in weight management research at the University of Cambridge who was not involved in the study, said swallowing a pill might be more attractive to patients than having to inject themselves.
She said: “We still do not know how durable these effects will be over longer periods of time.
“This study reinforces the growing recognition that obesity is a chronic, relapsing disease that often requires ongoing treatment and support.”
Orforglipron works similarly to obesity jabs by mimicking a natural hormone that reduces appetite and makes people feel fuller for longer.
In the US, where it is available, the lowest dose costs about US$149 per month, compared with more than US$1,000 a month for some GLP-1 injections, although US president Donald Trump has announced deals that aim to lower the cost of popular weight-loss drugs.
It is not known how much orforglipron would cost in the UK, as it has not yet been released to the market.
Similarly, rival manufacturer Novo Nordisk has an oral version of its injectable GLP-1 drug Wegovy, which has been approved in the US, with a UK decision pending.
The study included 376 participants in the US who had already been on GLP-1 jabs, tirzepatide, sold as Mounjaro, or semaglutide, sold as Wegovy, for more than a year and had successfully lost weight.
They were asked to stop the jabs and were given a pill containing either orforglipron or no drug, a placebo or dummy treatment, to take every day for a year. They were not told which they were taking.
At the end of the study, participants who took orforglipron kept more than 70 per cent of their earlier weight loss off, while the placebo group kept around 38 to 50 per cent off.
Side effects on the drug were common but mostly mild and included nausea, constipation and diarrhoea.
Nausea means feeling sick, while constipation and diarrhoea refer to changes in bowel habits that can make it harder or more frequent to pass stools.
Dr Simon Cork from Anglia Ruskin University said it is a “really important study” that addresses a key limitation of injectable, GLP-1 based weight-loss medicines, where patients can experience significant weight rebound after stopping them.
He said: “What is also important to note is that the decrease in blood pressure, lipids and blood glucose were also maintained in those patients taking oral medications.”
Lipids are fats in the blood, while blood glucose refers to blood sugar levels. That, in turn, could help reduce some of the longer-term health risks of obesity, such as heart disease.
