Myo-inositol is involved in several aspects of human reproduction. Elevated concentrations of myo-inositol in human follicular fluids appear to play a positive function in follicular maturity and provide a marker of good quality oocytes. Nevertheless its positive role in PCOS women is a consequence of a defect in the insulin signalling pathway (inositol-containing phosphoglycan mediators) that seems to be primarily implicated in the pathogenesis of insulin resistance