There are different types of long-acting contraceptive injections, and the duration of effective contraception after one injection varies from one month to two or three months. At present, the more commonly used long-acting contraceptive injections are monopregnanolone preparations and estrogen-progestin combination preparations, with an effective rate of more than 98%, which are more suitable for patients who have obvious gastrointestinal reactions to oral contraceptives. Estrogen-progestin combination preparation is the more commonly used long-acting contraceptive injection, usually one intramuscular injection, can be contraceptive for 1 month. The first intramuscular injection is given on the 5th and 12th day of the menstrual cycle, and then on the 10th to 12th day of each menstrual cycle, and menstruation usually occurs 12 to 16 days after the injection. This preparation has more side effects, so it is rarely used. Monoprogesterone long-acting contraceptive injections, including medroxyprogesterone hydrochloride contraceptive injections and pregnenolone contraceptive injections, are more suitable for breastfeeding women because they have less effect on the quality and quantity of breast milk. Methylhydroxyprogesterone hydrochloride contraceptive injection, which is given every 3 months, is effective in contraception. Heptynorgestrel contraceptive injection, intramuscular injection every 2 months. Consultation with a specialized doctor is recommended for specific cases.