Emergency contraceptive pills are effective when taken after 5 hours. Emergency contraceptive pills are effective when taken within 72 hours after sex, and this pill is taken after 5 hours to achieve contraceptive effect. However, the sooner the emergency contraceptive pill is taken after sex, the better the effect. After taking the pill, some people will have irregular vaginal bleeding, which belongs to withdrawal bleeding. The amount of bleeding can be treated as a menstrual period. It is recommended to take a good condom if you do not plan to get pregnant in the future. Emergency contraceptive pills should not be taken frequently, up to 3 times a year. After taking the pill, some people may have nausea, vomiting and other discomforts, so pay attention to drinking water and resting appropriately, and eat again 2 hours after taking the pill. Specific symptoms of discomfort, to consult a doctor in time.