Not having menstrual periods after taking progesterone is not necessarily very serious, the cause of the disease is different, the severity is different, such as pregnancy, the uterine lining is too thin, etc., usually not serious. Progesterone belongs to the progesterone class of drugs, and its effect is similar to the effect of the action of progesterone, therefore, it can be used for birth control and treatment of menstrual disorders and so on. When progesterone is used in the treatment of menstrual diseases, such as amenorrhea, its principle is to make the endometrium change to the secretory phase, and after stopping the drug, it can lead to endometrial shedding and bleeding, i.e., withdrawal bleeding, but the prerequisite is that there is a certain amount of oestrogenic effect, so that the endometrium reaches a certain thickness in order to play a role, so if the endometrium is too thin, the use of progesterone will not cause the endometrium to shed and bleed. It may take a few days after stopping progesterone to cause the lining of the uterus to slough off and bleed, and menstruation will not occur if the withdrawal time is too short. In addition, when a patient is pregnant, progesterone is used to protect the fetus and does not cause withdrawal bleeding. If the patient still does not have menstrual flow after stopping progesterone, she should consult a doctor in time, because there are many reasons for amenorrhea, besides the above mentioned possibilities, such as pituitary tumors, craniopharyngiomas, endometrial tuberculosis and so on, which may lead to amenorrhea, and then it will be more serious, and she needs to consult a doctor in a regular manner, and follow the doctor’s instructions for treatment.