It is a Fat Blocker: It acts as a magnet to dietary fat - resulting in weight loss. Fat Blockers are the simple, modern scientific development in weight control, containing the natural extract 'Chitosan,' which binds with the fat you eat, to prevent its absorbtion by the body. Chitosan acts as a magnet to dietary fat and resists digestion allowing the fat to pass naturally through the body resulting in weight loss. Also known as Fat Magnets, Calix, Strobby and Fat Busters.