Chitosan is a naturally occurring substance which binds to some fat in the digestive tract. The fat bound to the Chitosan is not metabolized by the body and is excreted. Optimum Nutrition's Chitosan Diet Formula is produced from Chitosan that is 90-95% deacetylated to improve solubility, chelation and emulsion characteristics. This stimulant-free weight-loss aid provides 1000 mg of deacetylated Chitosan and 200 mg Vitamin C in each serving.