Does ovary need D-chiro-inositol? 

This meta-analysis from 2012 highlights the importance of the right dose and ratios of myo-inositol and D-chiro-inositol in the effects observed with supplementation. In this randomized, placebo-controlled clinical study, PCOS patients were randomized into one of five groups: a placebo group, and four groups receiving increasing doses of D-chiro-inositol (300, 600, 1200 and 2400 mg) daily for eight weeks. Higher doses of DCI were associated with increased r-FSH and the number of immature oocytes, compared to the lower dose groups and placebo groups. The results suggest that increased DCI dosage is associated with worsening of oocyte quality and ovarian response. Proper dosage of DCI is essential to positive response in PCOS patents. 

References:

Isabella, R., Raffone, E. CONCERN: Does ovary need D-chiro-inositol?. J Ovarian Res 5, 14 (2012). https://doi.org/10.1186/1757-2215-5-14