Polycystic ovary syndrome (PCOS, also known clinically as Stein-Leventhal syndrome), which is an endocrine disorder that affects 5--10% of women. It occurs amongst all races and nationalities, is the most common hormonal disorder among women of reproductive age, and is a leading cause of infertility. The symptoms and severity of the syndrome vary greatly between women. While the causes are unknown, insulin resistance (often secondary to obesity) is heavily correlated with PCOS.