Yutin is a kind of contraceptive pill, belongs to the emergency contraceptive pill, often used for not good contraception or contraceptive failure of a remedy, to prevent accidental conception on the body damage. But it must be taken within 72 hours of intercourse to have an effect, the earlier you take the higher the rate of contraception. The main purpose is to change the viscosity of the cervix, which is not conducive to sperm entering the uterus through the cervix, and inhibit ovulation, so that sperm and eggs are not easily combined, thus achieving the purpose of contraception. It is convenient, economical and simple to take orally, widely used in clinical practice, and belongs to the hormone class of drugs. Occasional use is not very harmful to the body, but frequent use is likely to lead to endocrine disorders and menstrual disorders, and must be taken under the guidance of a doctor.