Orlistat or metformin combined with lifestyle chances in the management of obese patients with PCOS Prof.Xiangyan Ruan.MD.PhD. Dept.Of Gynecological Endocrinoloy,Beijing Obstetrics & Gynecological Hospital,Capital Medical University,China Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women of reproductive age. Lifestyle interventions, including diet, exercise and behavioral modification, improving the metabolic abnormalities of overweight and obese patients with PCOS, is recommended as first-line treatment. Lifestyle interventions combined with anti-obesity products may exert stronger effects improving endocrine abnormalities of obese PCOS patients. Anti-obesity products include orlistat, metformin, and inositol. However, the latter two products have not been approved as indication to get weight loss. Inositol still is not available in China. Therefore within a three monthly prospective randomized study we compared during treatment of 240 PCOS patients the efficay of orlistat versus metformin. All patients also got Diane-35 which is the routine basic therapy in most PCOS patients in China. All patients were overweight or obese (body mass index ≥ 24 kg/m2) with insulin resistance (fasting insulin > 10 mIU/L). Details will be reported. Our conclusion of this study is that Orlistat is more effective in reducing weight than metformin. Both orlistat and metformin showed a similar effect on reduction in insulin resistance. However, orlistat has less side-effects and is better tolerated compared to metformin.