In India Duphaston is approved and widely used for the treatment of progesterone deficiencies such as for management of dysmenorrhea, endometriosis, secondary amenorrhea, irregular cycles, dysfunctional uterine bleeding, pre-menstrual syndrome, threatened and habitual abortion, infertility due to luteal insufficiency, as well as part of hormone replacement therapy. One Indian study reported normalization of the cycle in 91.6% of women with menstrual problems after three cycles of therapy with dydrogesterone 10 mg given from 11th to the 25th day of the menstrual cycle. The mean cycle duration during dydrogesterone therapy in this study was noted to be 28.8 days, in contrast to 17.9 days (in the polymenorrhea group) and 50.6 days (in the oligomenorrhea group) before therapy. Furthermore, dydrogesterone also decreased the amount and duration of menstrual bleeding in this study.