Male contraceptive injections generally last for a relatively short period of time, with most lasting only about 1-2 months. The male contraceptive injection contains a large amount of testosterone, which is injected into the body to disrupt the secretion of hormones in the body, thereby inhibiting the secretion of gonadotropins in the human hypothalamus, which can affect the quality of male sperm and reduce the viability of sperm. In this way, the probability of female conception can be effectively reduced, but the testosterone entering the body will be metabolized from the male body within 1-2 months, at which point the contraceptive injection loses its effectiveness. It is also important to note that the shot is not a cure-all, but only reduces the probability of conception. The safest way is to choose to use condoms, which will not only reduce the probability of pregnancy, but also reduce the probability of sexually transmitted diseases.