Monastra, Giovanni, et al. Gynecological Endocrinology 33.1 (2017): 1-9.
D-chiro-Inositol (DCI), together with myo-inositol (MI), participates in insulin signaling as a component of inositol phosphoglycans, and this review examined their combined use in polycystic ovary syndrome (PCOS), which affects up to 10-15% of women of reproductive age.
The authors synthesized experimental and clinical evidence, including trials in which PCOS women received DCI alone at doses from 300 to 2400 mg/day (including 2.4 g DCI daily) or a combined MI plus DCI formulation at the physiological plasma ratio of 40:1, with one trial enrolling 100 PCOS women undergoing IVF-ET that was compared against a control group receiving DCI 500 mg.
Key Findings: Although DCI improved systemic insulin-related parameters on non-ovarian tissues, increasing DCI doses paradoxically worsened oocyte quality and ovarian response in non-obese, non-insulin-resistant PCOS women, consistent with the finding that the MI/DCI ratio in PCOS follicular fluid was only 0.2:1 versus a normal value near 100:1 and that 99% of the intracellular inositol pool is MI. The 40:1 MI plus DCI combination required lower FSH dosages, significantly improved oocyte quality and pregnancy rate, and ameliorated diastolic blood pressure, fasting glucose and insulin, insulin and glucose AUCs, HOMA index and lipids. MI alone increased ovulation frequency to 40% and clinical pregnancy rate to 33.3% versus 13.3%.
Gambioli, Riccardo, et al. Biomedicines 9.10 (2021): 1378.