The main ingredient of DANMEI emergency contraceptive pill is levonorgestrel, which on the one hand can achieve the effect of inhibiting ovulation and oocyte implantation; on the other hand, it can increase the concentration of cervical mucus and prevent the entry of sperm. This drug is safe, effective and has few side effects. It may cause mild nausea, vomiting, fatigue and other symptoms, which will disappear on their own soon and do not require special treatment. It should be noted that if women suffer from breast cancer, high blood pressure, diabetes, etc., the use of this drug is prohibited, the use of this drug will not affect the woman’s future fertility, very safe. It should be recommended to take good contraceptive measures during sexual intercourse to avoid unnecessary harm.