Taking melatonin will not affect the delay of menstruation because it works to improve the environment of the body by regulating its functions, increasing weight and promoting growth. Delayed menstruation is more often seen clinically in the state of pregnancy, which can cause delayed menstruation. If there is ovarian dysfunction, mental stress, strain, or business trip or obesity, it can also cause delayed menstruation. Therefore, in case of clinically delayed menstruation, it is important to go to the hospital in time for the appropriate examination to determine the cause of delayed menstruation through ultrasonography and urine pregnancy test paper.