Contraceptive injections and IUDs have their own advantages and disadvantages, which need to be discussed with respect to the existence of corresponding contraindications in patients and cannot be generalized. Contraceptive injection refers to the injection of estrogen and progesterone into a woman’s body to achieve contraception by inhibiting ovulation or altering the viscosity of the endometrium and cervical mucus, thus discouraging sperm fertilization and the implantation of a fertilized egg. Contraceptive injections are generally suitable for women who need long-term contraception, but are not suitable for people with unexplained arterial disease, heart disease, history of stroke, or history of liver disease. The IUD, also called IUD placement, is suitable for women in their reproductive years, and its main mechanism of action is that it can interfere with the fertilization of the egg and has toxic effects on sperm and embryos. The IUD is not suitable for people with acute inflammation of the reproductive tract, heavy bleeding from abortion, genital tumors, genital malformations such as mediastinum uterus, double uterus, severe systemic diseases, and people with menstrual disorders in the last 3 months, irregular bleeding from the vagina, and a history of copper allergy. It is effective for a longer period of time and requires regular follow-up to check the effectiveness of the device. Therefore, the contraceptive injection and the IUD should not be compared to each other, but should be chosen as the appropriate contraceptive method for your situation.