Finding the best therapeutic approach for PCOS: the importance of inositol(s) bioavailability

Broadening clinical evidence has markedly designated inositol(s) as a common and effective therapeutic approach for PCOS and infertility. Although considerable research has been focused on the use in clinical practice of myo-inositol (myo-ins) and D-chiro-inositol (D-chiro-ins), the two major inositol stereoisomers, less attention has been paid to their bioavailability. Therefore, the aim of this paper is to gather and analyze information on inositol(s) bioavailability, to better delineate its optimal concentration for scientific and clinical purposes. Throughout the search in PubMed, Google Scholar, and ResearchGate we identified only two studies that investigated the pharmacokinetic (PK) profile of different myo-ins administrations. This analysis found no advantage in terms of PK for single 4 g dosing of myo-ins compared to 2 g twice a day, which allowed to get a 24-hour coverage, contrary to the singular dose. Indeed, the differences regarding the area under the curve (AUC) between the two PK profiles are linked only to the maximum concentration (Cmax) but not to the time variable. In conclusion, splitting the therapeutic dosage of 4 g myo-ins in two distinct administrations seems to be the best approach for a full-day coverage.