The first NHS patients have been treated with a gastric balloon fitted in 15 minutes via a swallowed capsule.
The weight loss device is filled with water and reduces stomach capacity, helping users feel fuller faster.
Unlike other gastric balloons, it does not require surgery, endoscopy or anaesthesia.
Two patients swallowed the capsules at Musgrove Park Hospital in Somerset, with up to a dozen others due to be treated.
Professor Richard Welbourn, consultant bariatric surgeon at Somerset NHS Foundation Trust, said the balloon offered a “much improved experience for our patients”.
He added: “We are very pleased to be able to offer this new treatment, a first for the NHS, that offers clinically meaningful weight loss as part of a holistic programme involving dietary support and care.
“We expect that patients using the programme will lose 10-15% of their weight in four months, which improves quality of life and makes patients healthier.”
The balloon, made by Allurion, is swallowed by the patient during a 15 minute appointment.
An X-ray confirms the correct placement in the stomach and 550ml of water is put into the balloon via the tube.
A second X-ray is then taken to check the balloon is full and sitting well in the stomach. The tube is then removed.
After around four months, a time-activated release valve automatically opens, allowing the water-filled balloon to empty and pass naturally through the gastrointestinal tract.
Almost two-thirds of adults in England are overweight and more than a quarter are classed as obese.
Obesity – defined as a body mass index of over 30 – increases the risk of serious health conditions including type 2 diabetes, coronary heart disease and some types of cancer.
The treatment was approved by the National Institute for Health and Care Excellence (Nice) in 2020.
The medicines assessor noted that there was good evidence that the device was effective for short term use for medical reasons, but there was less evidence of benefits for long-term weight loss so it should only be with that aim in a research context.
It said the balloon must be used alongside a nutrition and behaviour modification programme supervised by a qualified healthcare professional.
Allurion said it had been in talks with NHS trusts about rolling it out since the approval. It claimed the balloon could save the NHS significant time and money as it is less invasive than bariatric surgery and does not require a hospital stay or use of a surgical theatre.
Dr Shantanu Gaur, founder and chief executive of Allurion, said: “We are looking forward to expanding this partnership and benefiting many more NHS patients in the months and years to come.”