Insulin, the most important hormone which regulates the body’s use of sugar, appears to play an important role in the development of polycystic ovary syndrome (PCOS). It appears that many women with polycystic ovary syndrome (PCOS), produce too much insulin or the insulin they produce does not function well. Insulin affects the maturation of the ovarian follicles and interrupts ovulation. As a result the ovaries produce hormones (including androgens) in incorrect proportions. The pituitary gland senses that the ovary is not working properly and in turn releases abnormal amounts of luteinising hormone(LH) and follicle-stimulating hormone (FSH). The irregularities of insulin metabolism in patients with polycystic ovary syndrome appears to contribute to their tendency to gain weight and their difficulty to lose it. These women have also higher chances of developing diabetes later in life.