Megestrol tablets, also known as medroxyprogesterone acetate tablets or progesterone tablets, are usually taken for 5 days and menstruation will occur after about 1 week of stopping the medication. Medroxyprogesterone acetate tablets are a progestin-based oral medication that can be taken to induce menstruation when a woman has a delayed period, when the endometrium has grown to have about 1.2 cm, and when pregnancy is ruled out. Occasionally taking 1-2 times of this drug can play a role in adjusting the menstrual cycle, but it should not be taken regularly, otherwise menstrual disorders or side effects of taking the drug may occur. When women have delayed menstruation, it is best to go to the hospital for a sex hormone test or gynecological ultrasound to try to find the cause of the delayed menstruation and use treatments that are safer, such as mental relaxation, regularity, or taking hormonal drugs to adjust the menstrual cycle.