Short answer
A gastric balloon (intragastric balloon) is a soft balloon placed in the stomach through the mouth, without surgery, and filled with salt water so that you feel full sooner. Most balloons stay in for up to about six months and are then removed. In trials, people lost several percentage points more body weight than with lifestyle measures alone, but some of that loss tends to return after removal. How much it helps depends largely on the diet and activity changes made while it is in place.
Key points
- Placed through the mouth under sedation or local anaesthetic; no cuts are made.
- Usually left in for up to six months, then removed with an endoscope (camera tube).
- Pooled trials show about 5 percentage points more total body weight loss than standard care.
- Nausea, vomiting and stomach pain are common in the first days; about one in five balloons in trials came out early.
- Rare serious risks include deflation causing a blockage, pancreatitis, ulcers and stomach perforation.
How a gastric balloon is placed
The NHS lists the gastric balloon among the main types of weight-loss procedure, alongside gastric bypass, gastric band and sleeve gastrectomy.1 A camera is first passed through the mouth to check the stomach; the empty balloon then goes down into the stomach and is filled with salt water through a thin tube. The NHS says it usually takes around 20 minutes, and you may be offered a local anaesthetic or a sedative.1
Mayo Clinic describes the procedure as done under sedation as an outpatient, with most people going home one to two hours afterwards. The balloon stays in for up to six months and is then removed in the same way; whether a new one is placed depends on the plan agreed with the doctor.2 The balloon takes up space in the stomach, so less food is needed to feel full.
| Feature | Gastric balloon | Sleeve or bypass surgery |
|---|---|---|
| Cuts or stapling | None; placed through the mouth1 | Keyhole surgery under general anaesthetic1 |
| Duration | Usually up to six months, then removed2 | Permanent change to the stomach1 |
| Typical BMI range discussed | 30 to 402 | Usually 40 or more, or 35 with a related condition4 |
| Durability | Some weight tends to return after removal3 | Long-term weight loss shown over years5 |
Who may be considered
Mayo Clinic describes candidates as people with a body mass index (BMI) between 30 and 40 who are willing to make lifestyle changes and attend follow-up and behavioural therapy. People who have had previous surgery on the stomach or oesophagus (gullet) are not candidates, and screening is needed because a balloon is not suitable for everyone who is overweight.2
That BMI range overlaps with people who might also be offered weight-loss medicines, and sits partly below the usual UK thresholds for surgery.4 See who qualifies for weight-loss surgery and weight-loss injections vs surgery.
How much weight do people lose?
A 2022 systematic review and meta-analysis pooled trials comparing balloons with standard medical therapy (lifestyle advice, sometimes with medicines). At six months, people with a balloon had lost about 5.5 percentage points more of their total body weight; at 12 months the difference was about 5.3 points, based on fewer studies.3 In one included trial, total body weight loss was 14.2% against 4.8% at six months, falling to 9.2% against 5.2% at 12 months, after the balloon had been removed.3
The reviewers noted weight regain after removal in several trials and very little data on placing a second balloon.3 The evidence that a balloon gives more short-term weight loss than lifestyle measures alone is Moderate; evidence on lasting benefit beyond a year is Limited. Mayo Clinic stresses that without lasting changes to diet and exercise, weight can be regained even when the device has worked as intended.2
Side effects and risks
Expected effects are common: Mayo Clinic says about one-third of people have pain and nausea soon after insertion, usually lasting a few days.2 In the pooled trials, nausea, vomiting and abdominal pain were the most frequent problems, and about 20% of participants had the balloon removed before six months, either because of side effects or at their own request.3
Serious complications are rare but recognised. They include the balloon deflating and moving into the gut, where it can cause a blockage needing another procedure; overinflation; acute pancreatitis (inflammation of the pancreas); ulcers; and perforation (a hole) in the stomach, which may need surgery.2
When to seek medical advice
Mayo Clinic advises contacting your doctor if you have nausea, vomiting or abdominal pain at any time after the balloon is placed, beyond the expected first few days.2 Rare complications such as deflation with blockage, pancreatitis or perforation may need another procedure or surgery.2
Common questions
Is a gastric balloon surgery?
No; it is placed through the mouth using a camera, with no cuts, usually under sedation or local anaesthetic.1
How long does the balloon stay in?
Usually up to six months, after which it is removed endoscopically.2
Will the weight stay off after removal?
Some weight commonly returns; trials included in the 2022 review reported regain after removal.3 Lasting diet and activity changes make the biggest difference.2
Is it the same as endoscopic sleeve gastroplasty?
No; endoscopic sleeve gastroplasty uses stitches placed through the mouth to fold and narrow the stomach, rather than a removable balloon.1 See what endoscopic sleeve gastroplasty is.
Bottom line
A gastric balloon is a temporary, non-surgical aid that gives modest extra weight loss over lifestyle measures while it is in place. Early side effects are common, serious complications are rare, and whether the benefit lasts depends on the habits built during those months.
Related reading
- Bariatric surgery overview
- What is endoscopic sleeve gastroplasty?
- Weight-loss injections vs surgery: how do they compare?
- Who qualifies for weight-loss surgery?
Sources
- NHS. Weight loss surgery: what it is, and how it’s done. NHS website. https://www.nhs.uk/tests-and-treatments/weight-loss-surgery/what-is-weight-loss-surgery/ and https://www.nhs.uk/tests-and-treatments/weight-loss-surgery/how-its-done/. Accessed 5 November 2026.
- Mayo Clinic. Intragastric balloon. Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/tests-procedures/intragastric-balloon/about/pac-20394435. Accessed 5 November 2026.
- Lee SY, Lai H, Chua YJ, Wang MX, Lee GH. Endoscopic bariatric and metabolic therapies and their effects on metabolic syndrome and non-alcoholic fatty liver disease: a systematic review and meta-analysis. Frontiers in Medicine; 2022;9:880749. doi:10.3389/fmed.2022.880749. https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.880749/full
- NHS. Obesity: treatment. NHS website. https://www.nhs.uk/conditions/obesity/treatment/. Accessed 5 November 2026.
- Salminen P, et al. Effect of laparoscopic sleeve gastrectomy vs Roux-en-Y gastric bypass on weight loss, comorbidities, and reflux at 10 years in adult patients with obesity: the SLEEVEPASS randomized clinical trial. JAMA Surgery; 2022;157(8):656-666. doi:10.1001/jamasurg.2022.2229. https://www.pubmed.gov/35731535/
Article history
- — First published.