The 72-hour pill, also known as the emergency contraceptive pill, is a remedial contraceptive method that is most effective when taken within 72 hours. Emergency contraceptives are divided into estrogen-progestin combination formulations, monoprogestin formulations and anti-progestin formulations. Estrogen-progestin combination preparations, such as levonorgestrel tablets, and monoprogestin preparations, such as levonorgestrel tablets, are recommended to be taken within 72 hours after unprotected sex and again after 12 hours to reinforce their efficacy. The difference between the two is the difference in dosage, and the medication should be taken as prescribed by the doctor or in accordance with the instructions. It should be noted that anti-progestational agents, such as mifepristone, can be taken within 120 hours of unprotected sex. The 72-hour pill is an emergency contraceptive and should not be used as a regular method of contraception.