The 40:1 myo-inositol/D-chiro-inositol plasma ratio is able to restore ovulation in PCOS patients: Comparison with other ratios

OBJECTIVE: The aim of this clinical trial was to evaluate the efficacy of seven different ratios between two inositols stereoisomers, myo-inositol (MI) and D-chiro-inositol (DCI), in the therapy of polycystic ovary syndrome (PCOS). PATIENTS AND METHODS: fifty-six PCOS patients (8 for each group) were treated by oral route using the following formulations: DCI alone, and 1:3.5; 2.5:1; 5:1; 20:1; 40:1, 80:1 MI/DCI ratio. They received 2 g of inositols twice a day for 3 months. The primary outcome was ovulation, the secondary outcome included the improvement of FSH, LH, Sex Hormone Binding Globulin (SHBG), 17-beta-Estradiol (E2), free testosterone, basal and postprandial insulin levels, as well as HOMA index, BMI and menses. RESULTS: We found that the 40:1 MI/DCI ratio is the best for PCOS therapy aimed at restoring ovulation and normalizing important parameters in these patients. The other formulations were less effective. In particular, a decreased activity was observed when the 40:1 ratio was modified in favour of DCI. CONCLUSIONS: Our data demonstrated that DCI activity is beneficial mainly at a specific ratio with MI, whereas the increase of DCI causes the loss of the beneficial effects at reproductive level. These results in humans validate a previous preclinical study with different MI/DCI ratios carried out in an experimental model of PCOS mice.