Insulin resistance has important implications in the pathogenesis of the polycystic ovary syndrome (PCOS) and insulin-sensitizing drugs are considered a useful therapeutic approach.

Reduction of insulin levels with administration of insulin sensitizing agents has been found to be beneficial in lowering both hyperinsulinemia, hyperandrogenemia, and restoring ovulation. Metformin alone or in combination with oral contraceptives (OCs) has been widely used in the long term treatment of women with PCOS in whom it modifies the ovarian morphology, improves intraovarian androgen levels, and enhances systemic and local insulin resistance. Despite to these beneficial effects, several side effects have been reported due to the long term administration of this drug.

In the recent years, inositol has found more and more space in the reproductive clinical practice. Indeed, inositol have been classified as "insulin sensitizing agent" and it is mainly used as a chronic treatment for PCOS. Inositol exists in 9 different isomers and in particular several studies on Myo-inositol and D-chiro-inositol were reported.

In this study myo-inositol versus D-chiro-inositol treatments were compared to placebo in women with PCOS and with or without insulin resistance.

Inclusion Criteria:

• Women fulfilled two out of three diagnostic criteria for PCOS

Exclusion Criteria:

• Women with pre-existing secondary endocrine disorders
• Women with personal history of hypertension, diabetes mellitus or cardiovascular disorders
• Women who received treatment with other drugs for the previous 6 months before entering the study.