The aim of the present study is to evaluate the effect of increasing the proportion of D-chiro-inositol (DCI) in a combination with myo-inositol (MYO) in improving fertility in women with polycystic ovarian syndrome (PCOS). Sixty women diagnosed with PCOS will randomly take twice a day for 12 weeks a capsule containing 550 mg of myo-inositol and 150 mg of D-chiro-inositol or capsules containing 550 mg of myo-inositol and 13.8 mg of D-chiro-inositol.