There are many types of emergency contraceptive pills, and they are not a single drug. Different types of emergency contraceptive pills do not take the same amount of time to be completely metabolized in the body, but most of them are completely metabolized in about 3-5 days. However, even if the emergency contraceptive pill is completely metabolized, some effects on the body last for a longer period of time. The emergency contraceptive pill may cause withdrawal bleeding in about 1 week and may affect the endocrine system to varying degrees for up to 1 month after taking it. In order to avoid some side effects of emergency contraceptive pills, in principle, the interval between consecutive doses of emergency contraceptive pills should not be less than 3 months, and the number of doses should not exceed 3 times within 1 year.