Polycystic took progesterone or do not come to menstruation is common in pregnancy, endometrial thinning, estrogen lowering and other reasons. 1. Pregnancy: the continuous action of progesterone during pregnancy will prevent the endometrium from shedding to ensure the normal development of fertilized eggs and embryos, so taking progesterone during pregnancy will not lead to menstruation. 2. The endometrium is too thin: common in the abortion or malnutrition of the population, need to supplement a certain amount of estrogen to increase the thickness of the endometrium and then use progesterone in order to menstruation, single progesterone will not come to menstruation. 3. lower estrogen: polycystic ovary syndrome patients with endocrine disorders, low estrogen, progesterone alone can not come to menstruation, should be supplemented with estrogen and progesterone in order to make the menstrual cycle stable. Polycystic take progesterone or not menstruation, it is recommended to seek medical help in a timely manner to find out the reasons with the help of the doctor, do not take medication without authorization, in order to avoid adverse consequences.