Emmenagogues are herbs which stimulate blood flow in the pelvic area and uterus, and some actually stimulate menstruation.

Women have used plants such as mugwort, parsley and ginger to prevent or terminate early pregnancy. Others use emmenagogues to stimulate menstrual flow when menstruation is absent for reasons other than pregnancy, such as hormonal disorders or conditions like oligomenorrhea (infrequent or light menses).