Orlistat is used in the management of obesity. It reduces fat absorption in the gastrointestinal tract.

Mechanism of action

Pancreatic lipase inhibitor


NICE have defined criteria for the use of orlistat. It should only be prescribed as part of an overall plan for managing obesity in adults who have:
  • BMI of 28 kg/m^2 or more with associated risk factors, or
  • BMI of 30 kg/m^2 or more
  • continued weight loss e.g. 5% at 3 months
  • orlistat is normally used for < 1 year

Adverse effects

  • faecal urgency/incontinence
  • flatulence