Yutin is generally eaten within 72 hours after the event may have an effect, the sooner you eat the better. If more than 72 hours, the effect may not be good. Yuktin is an emergency contraceptive and should not be taken more than 3 times a year. Because the dose of progestin is very large, eat more may affect the menstrual cycle, affect future ovulation, endocrine, and even more serious may affect the ovarian function. It is best to use short-acting oral contraceptives, including Ursine or Ursine, Daing-35 and Mafulon. These drugs have very few side effects and do not have a great impact on the menstrual cycle, but can instead regularize it.