A study conducted on 20 lean women with polycystic ovary syndrome demonstrated the efficacy of D-chiro-inositol in reducing circulating insulin and serum androgens, and improving some of the metabolic abnormalities such as increased blood pressure and hypertriglyceridemia. The results showed that in 10 women who were administered D-chiro-inositol, the mean (± standard error) area under the plasma insulin curve after oral administration of glucose reduced remarkably from 8,343 ± 1,149 mU/mL/min to 5,335 ± 1,792 mU/mL/min in contrast to no significant change in the placebo group. In addition, serum free testosterone concentration decreased by 73% from 0.83 ± 0.11 ng/dL to 0.22 ± 0.03 ng/dL. This was reported to be a significant change in comparison with essentially no change in the placebo group. Moreover, 6 out of 10 women (60%) in the D-chiro-inositol group and 2 out of 10 women in the placebo group (20%) ovulated. Reductions were also noticed in systolic and diastolic blood pressures, as well as plasma triglyceride concentrations in the D-chiro-inositol group in comparison with the placebo group, in which either blood pressure increased or triglyceride levels were reduced minimally.