The U.S. Food and Drug Administration (FDA) released a press announcement on May 26, 2010 to advise consumers and health care professionals of the potential rare incidences of severe liver injury recently experienced by some patients utilizing weight-loss medications containing Orlistat. The principal marketed forms of this fat-blocking compound are known as Xenical and Alli. Xenical is available by prescription only and contains 120 mg of Orlistat; while Alli is sold over-the-counter and contains 60 mg of Orlistat. It is estimated that 40 million individuals worldwide have utilized one of these weight-loss drugs. The FDA has reviewed a total of 13 confirmed cases of severe liver injury reported by individuals taking Orlistat. All of these cases, with the exception of one, were reported outside of the U.S. The one domestic case involved the use of the less potent Orlistat-containing substance, Alli. Unfortunately, the relationship between severe liver injury and Orlistat use has not been identified. Consequent to these new findings, the FDA has approved label revisions for Xenical and Alli to reflect this rare occurrence. Orilistat is a lipase inhibitor, and therefore promotes weight loss by blocking up to 30% of dietary fat in the intestinal tract. Positive outcomes associated with Orlistat consumption include lower systolic blood pressure, decreased waist circumference, and a reduction of LDL cholesterol, fasting serum glucose, and insulin levels. Orlistat is recognized to cause unpleasant gastrointestinal side-effects such as gas, rectal discharge, fatty bowel movements, and fecal urgency. Furthermore, significant fat consumption in conjunction with Orlistat use results in diarrhea and rectal leakage. These negative side-effects should not be confused with the signs and symptoms of potential liver injury. The FDA advises consumers and healthcare providers become familiar with the signs of injury to the liver including excessive itching sensations, yellow eyes or skin, dark urine, loss of appetite, or light-colored excrement.