Dysmenorrhea is a pathological symptom of menstruation. During dysmenorrhea, the pain occurs primarily in the lower abdomen and back (1, 2), and has a considerable impact on the quality of life (QOL) and work of affected women (1). Dysmenorrhea is divided into the categories of primary dysmenorrhea and secondary dysmenorrhea. Dysmenorrhea without underlying organic disease is diagnosed as primary dysmenorrhea (3). It involves increased production of endogenous bioactive substances such as prostaglandin in the late secretory endometria during the menstrual cycle, and it results in uterine hypercontraction, with vasospasm and ischemia in the myometrium at the time of menstruation (4). Therefore, effective Received May 22, 2019; revised September 9, 2019; accepted September 12, 2019; published online November 11, 2019. Y.O. is a medical expert contracted to Mochida Pharmaceutical Co., Ltd. and reports consulting fees from Mochida during the conduct of the study. K.H. was an employee of Mochida Pharmaceutical Co., Ltd., during the conduct of the study. S.K. was an employee of Mochida Pharmaceutical Co., Ltd., during the conduct of the study. Sponsored by Mochida Pharmaceutical Co., Ltd.

Dysmenorrhea is a pathological symptom of menstruation. During dysmenorrhea, the pain occurs primarily in the lower abdomen and back (1, 2), and has a considerable impact on the quality of life (QOL) and work of affected women (1). Dysmenorrhea is divided into the categories of primary dysmenorrhea and secondary dysmenorrhea. Dysmenorrhea without underlying organic disease is diagnosed as primary dysmenorrhea (3). It involves increased production of endogenous bioactive substances such as prostaglandin in the late secretory endometria during the menstrual cycle, and it results in uterine hypercontraction, with vasospasm and ischemia in the myometrium at the time of menstruation (4). Therefore, effective Received May 22, 2019; revised September 9, 2019; accepted September 12, 2019; published online November 11, 2019. Y.O. is a medical expert contracted to Mochida Pharmaceutical Co., Ltd. and reports consulting fees from Mochida during the conduct of the study. K.H. was an employee of Mochida Pharmaceutical Co., Ltd., during the conduct of the study. S.K. was an employee of Mochida Pharmaceutical Co., Ltd., during the conduct of the study. Sponsored by Mochida Pharmaceutical Co., Ltd.