Luteinizing hormone (progesterone), also known as progesterone hormone and luteinizing hormone, is the main biologically active progesterone secreted by the ovaries. It has significant morphological effects in the body on the estrogen-excited endometrium and is necessary for the maintenance of pregnancy. I. The specific time of progesterone injection for birth control needs to be decided according to the progesterone value. 1, progesterone value to reach the ideal value: that is, to reach 25ng/ml can gradually reduce the amount, after reducing the amount of general to continue to apply a week, again recheck progesterone, according to the progesterone situation to choose whether to stop the drug; 2, progesterone value does not reach the ideal value: after the injection of progesterone injection, progesterone still does not reach the more ideal situation, that is, not to reach 25ng/ml, in general, need to increase the amount, and continue for a week and then recheck . Second, the role of progesterone injections for birth control The low progesterone in early pregnancy tests suggests luteal insufficiency, progesterone injections can prevent the risk of preterm abortion or miscarriage. In addition, the lack of progesterone can endanger the development of the fetus, so progesterone injection can promote fetal development. Third, progesterone injection precautions Progesterone injection need to pay attention to the following matters: 1, injection to avoid too fast: progesterone injection belongs to the oil, the speed is too fast easy to make patients appear unbearable distension; 2, to determine whether the progesterone is normal: progesterone injection belongs to the progesterone preparation, before using the drug to determine the progesterone level decline caused by miscarriage before suitable for use; 3, pay attention to adverse reactions: after use may appear Headache, nausea and dizziness, weakness, hives, breast swelling, swelling, weight gain and other adverse reactions; 4, contraindicated groups: patients with kidney disease, heart disease edema, hypertension should be used with caution; 5, the use of natural preparations: to avoid the long-term use of a large number of synthetic progesterone injection, prone to female fetus masculinization.