Strictly speaking, there are three types of contraceptives: emergency contraceptives, short-acting contraceptives and long-acting contraceptives. 24-hour contraceptives should belong to the category of emergency contraceptives, and there are two types of emergency contraceptives: 1. Mifepristone, which must be taken within 72 hours after sex, the earlier the effect, the better the effect can be 99%. 2. Levonorgestrel, whose trade name is Yutin, must be taken within 72 hours after sex, and the two tablets are separated by 12 hours. The time interval is 12 hours. It is worth reminding everyone that no matter what type of contraceptive drug has its side effects, which can lead to thrombosis, cardiovascular disease, osteoporosis and other diseases, should be used under the guidance of a professional obstetrician and gynecologist in a regular hospital, do not take it on your own. There are many contraceptive methods, so you should consider them together and choose the one that suits you best and has the least side effects.