In the UK, weight loss surgery is performed at several regional NHS hospitals which are commissioned by the Department of Health to provide this service. Each hospital is commissioned to provide a maximum number of these operations per year. Generally, individuals with a higher BMI and multiple medical conditions are referred for surgery. However, almost all individuals approaching their GP will need to go through a weight loss program and pscyho-therapy for a variable period of time before being referred for consideration of surgery on the NHS. This process is highly variable depending on where you live and the amount of NHS funding available for surgery locally. Timing from first consultation to surgery can take anywhere from 1 to 3 years and surgery is not guaranteed.
There are also multiple private providers throughout the UK who accept self-referring patients. It is always advisable to let your GP know your plans even if you decide to have weight loss surgery in the private sector.