In a Japanese study, two herbal medicine prescriptions administered alternately within the menstrual cycle were found to have powerful antidysmenorrhoeic effects. The two prescriptions were Shakuyaku-kanzo-to (Shao Yao Gan Cao Tang/Peony & Licorice Decoction) and Toki-shakuyaku-san (Dang Gui Shao Yao San/Tangkuei and Peony powder). All 17 dysmenorrhea patients in the study, including recurrent endometriotic and adenomyotic patients obtained complete relief within three months. Nine of 12 patients treated with the herbal therapy ovulated and all three secondary ammenorrhoea patients with moderate levels of serum estradiol, but none of the three secondary amenorrhoea patients with little serum estradiol, also ovulated. One of the treated patients, who had a history of 10 repetitive spontaneous abortions. carried the 11th pregnancy to term. (Clin Exp Obstet Gynecol. 2003;30(2-3):95-8).