Patients are not able to retain the balloons for more than 90 days but the hope is that the treatment will help them make lifestyle changes which they will then be able to maintain once the balloons have been removed. Obalon costs from £2,995 for a two-balloon treatment. It is currently only available privately. It is aimed at people who are not sufficiently overweight to qualify for weight-loss surgery. Clinical trials in the UK and in the U.S. have shown that patients lose an average of 1st 3lbs in 12 weeks.