To treat anovulatory women with high plasma LH levels with unkei-to.A total of 100 patients with polycystic ovary syndrome (n = 38) or non-polycystic ovary syndrome (n = 62) were allocated randomly into two groups. Endocrine levels (FSH, LH and estradiol), follicle growth and response to unkei-to were compared for 52 subjects in the unkei-to group and 48 subjects in the control group.Unkei-to induced significant decreases in plasma LH in polycystic ovary syndrome and non-polycystic ovary syndrome with high LH levels. Plasma estradiol levels increased significantly (43.5%) in eight weeks of treatment with unkei-to. Significant development of the dominant follicle was also observed in patients treated with unkei-to. When women suffering from ovulatory failure or irregular menstruation and having high plasma LH concentration were treated with unkei-to for eight weeks, a reduction in the serum LH level of at least 1 SD from baseline was noted in 45.5% of polycystic ovary syndrome patients and in 80.0% of non-polycystic ovary syndrome patients. The mean rate of reduction of serum LH was 22.2 +/- 35.7% in polycystic ovary syndrome patients and 49.7 +/- 15.3% in non-polycystic ovary syndrome patients. This reduction was significant in the non-polycystic ovary syndrome patients (P = .030). The rate of menstrual cycle improvement, including successful ovulation, was 50.0% in the polycystic ovary syndrome group and 60.0% in the non-polycystic ovary syndrome group, with no significant difference between the two groups.