The term “birth control pills” nowadays usually refers to “short-acting combined oral contraceptives”. Their active ingredients are an estrogen plus a progestin. Since the 1960s, when the first combination oral contraceptive, Enovid, became available in the United States, oral hormonal contraception has shown reliable results. However, with the widespread use of the pill, some adverse effects of the pill, such as obesity, tumors, blood clots, and liver damage, were also discovered at that time, so the composition of the pill was continuously improved again. Considering the inconvenience caused by daily dosing, long-acting preparations, contraceptive injections, subcutaneous implants, and intrauterine slow-release systems were developed, but these preparations eventually did not become mainstream due to various reasons. At present, the short-acting combination oral contraceptive pill still occupies the main stage of pharmaceutical contraception. There are reasons why it is so popular. First, the principle of oral contraceptives oral contraceptives mainly through the simulation of human ovarian secretion of estrogen and progesterone to inhibit the pituitary gland to start the “ovulation process”, to achieve the purpose of contraception. Ovulation is initiated under the regulation of many factors in the hypothalamus, pituitary gland and ovaries. In the menstrual cycle, the egg is usually expelled from the ovary on the 14th day before the next menstrual period. During the period between the last menstrual period and ovulation, the ovaries gradually produce more estrogen, and when estrogen reaches its peak, the pituitary gland produces the “ovulation” command and the ovaries expel the egg. After the eggs are expelled, the ovaries secrete not only estrogen, but also progesterone, which prepares the woman for pregnancy. If conception is successful at this point, the pituitary gland is instructed to “stop ovulating” and to avoid ovulating again during pregnancy. The principle of oral contraceptives is to simulate the state of pregnancy, so that the body always has a certain amount of estrogen and progesterone levels, and the brain thinks that the body is in a state of pregnancy, and the pituitary gland and ovaries start to take a holiday break, during which ovulation is no longer possible and conception is impossible [2]. Misconceptions about oral contraceptives Many people talk about hormones, but this “hormone” is not the other “hormone”. It is true that glucocorticoids can cause obesity, gastric ulcers, osteoporosis and other side effects when used in large quantities to treat nephritis or other rheumatic immune diseases, but this is not true for all hormones. Although the estrogen and progestin in oral contraceptives are synthetic, their effects are consistent with the hormones secreted by the human body itself, and they simulate the natural state of the human body. Therefore, there is no need to worry about these side effects. Some people believe that hormone-containing birth control pills have carcinogenic effects, but in fact, it is now clear that combined oral contraceptives can reduce the risk of endometrial and ovarian cancer and have a protective effect on women’s uterus and ovaries. As for breast cancer, some studies have suggested that compounded oral contraceptives may slightly increase their incidence (relative risk 1.24) [3]. However, this relative risk increase is actually very small, even night shifts increase the risk of breast cancer by 1.4-1.5 times (see: “Staying up late causes breast cancer?”). . That said, regular mammograms are necessary whether you take medication or not. In addition, long-term studies have found that combined oral contraceptives are not teratogenic and are rapidly metabolized, allowing pregnancy the month after discontinuation without affecting offspring growth and development [4]. III. Where the advantages of oral contraceptives lie The continuous development of oral contraceptives has been accompanied by the reduction of estrogen and the improvement of the effectiveness of progestin in contraceptives. In the early days, because synthetic progestins had a small amount of androgenic activity, users could experience adverse effects such as abnormal sugar and lipid metabolism, weight gain and acne. The third-generation progestins introduced in the 1980s have reduced androgenic activity, while progestin activity is unchanged or stronger, and the adverse effects are lower. The third-generation progestin-based combination oral contraceptives include Mafolone, Meclizine, and Mintin even. In recent years, new contraceptive pills such as Dareng-35 and Ursine have been introduced, which contain new progestins with anti-androgenic activity, and thus can also be used to treat polycystic ovary syndrome, female androgenetic alopecia, and moderate to severe acne in women. In addition, the pill acts directly on the ovulation link, without any interference with the sexual act itself, and thus does not affect the pleasure experience of both men and women. The absence of ovulation also eliminates ectopic pregnancy (i.e., “ectopic pregnancy”), making it more suitable for women with a history of ectopic pregnancy. (Oral contraceptive pill is a higher safety factor than condoms, see: “contraception, reliable methods are the most important”) Fourth, who should be careful with oral contraceptives Because estrogen and progesterone on the other systems of the body will also have a certain effect, taking the pill at the beginning of some women can appear short-term discomfort, such as early pregnancy reaction, dizziness, nausea, loss of appetite, etc.. In addition, some women may also experience irregular vaginal bleeding, which mostly occurs after missing the pill. The above reactions will disappear gradually as the duration of the pill increases. If the physical discomfort with the pill persists, you should seek medical attention as soon as possible to replace the drug or other forms of contraception. V. What are the adverse effects of long-term use of the pill on the human body? Current research has focused on cardiovascular disease, blood clots, and malignancies. In terms of cardiovascular events, it was found that there is a positive synergistic effect between smoking and taking the pill on the risk of myocardial infarction [3]. That is, for non-smokers, the pill is safe, whereas for smokers, the pill amplifies the cardio-vascular damaging effects of smoking. Contraceptives also have a slight blood pressure elevating effect and should be avoided in patients with hypertension. With regard to thrombotic events, although the incidence is low, the pill is currently considered to increase the risk of venous thrombotic events overall (approximately 1.8 cases per 10,000 women per year). The incidence of venous thrombotic events has been significantly reduced with newer contraceptives compared to older generations of contraceptives [3]. However, the risk of venous thrombotic events has recently been found to be slightly higher with newer contraceptives containing drospirenone, such as euselenone, than with the previous generation of contraceptives containing levonorgestrel, alerting women taking these pills to the need for venous thrombotic events. If you experience headache, chest pain, abdominal pain, leg pain or swelling, or eye discomfort while taking the pill, you should seek medical attention. In terms of malignancy, in addition to the slight increase in the incidence of breast cancer mentioned earlier, the pill can mildly increase the incidence of liver cancer in those who are positive for hepatitis B surface antigen, therefore, oral contraceptives are not recommended for hepatitis B patients in China. However, for people with non-regular sexual partners, oral contraceptives do not provide protection against sexually transmitted diseases and condoms are a more appropriate form of contraception. Additional note: The following are not “birth control pills” as discussed above. Long-acting pills: Long-acting oral contraceptives have been developed in the past for ease of use, and can be taken for about one month at a time, but they have a large hormonal content, many side effects, and can accumulate in the body. Emergency contraception: Emergency contraception is a remedial contraceptive method used to prevent unwanted pregnancy after unprotected sex or contraceptive failure. The emergency contraceptive pill contains five times the amount of progestin as the short-acting pill, and in addition to causing heavier adverse reactions such as nausea, vomiting and irregular vaginal bleeding, it also interferes greatly with the menstrual cycle. Therefore, the emergency contraceptive pill should only be used as a remedial measure and not as a regular contraceptive method. CONCLUSION: The short-acting compound oral contraceptive pill is a reliable and safe method of contraception for young women with regular sexual partners, non-smokers and non-hypertensives.