Progesterone is a progestin, and the principle of urging menstruation is through the supplementation of progesterone, with retreating endometrial bleeding occurring 3-5 days after stopping the drug. If there is no other pathology present, most people can have a period after stopping progesterone. If menstruation does not come or comes rarely, it is recommended to rule out whether endometrial damage or estrogen itself is abnormal, such as premature ovarian failure, uterine developmental abnormalities or uterine adhesions and other diseases, the progesterone test results will be negative. Oral progesterone should not be taken without authorization, and ultrasound and hormone tests are recommended to rule out contraindications before taking the drug. If the thickness of the lining is >7mm, it will usually come after taking it; while for <5mm the effect is not good, it can be through estrogen-progestin therapy.