In the past, PCOS treatment was focus on ovulation induction for infertility, oral contraceptives for irregular bleeding, and androgens antagonists for hirsutism or acne. In later years insulin sensitizing agents have been used to reduce hyperinsulinemia, improve ovary function and associated metabolic abnormalities. Metformin (MTF), a biguanide, usually used in obese patients with type 2 diabetes,inhibits glucose hepatic production,decreases insulin secretion and increases peripheral insulin sensitivity.