Hormones are the initiating factor of acne. Androgens stimulate sebaceous cells to secrete more sebum, which increases the secretion of sebum and stimulates hyperkeratosis of hair follicle ducts, making the hair follicle wall hypertrophic and preventing sebum excretion. This is the initiating factor of acne. Estrogen inhibits the function of sebaceous glands and reduces the occurrence of acne. In men, the organs that secrete androgens are the testes and adrenal glands (eunuchs who were castrated in the ancient court had fewer androgens and did not suffer from acne); in women, the ovaries, placenta and adrenal glands also secrete androgens, and if the ratio is out of balance with feminine hormones, this also constitutes an acne-initiating factor. Second, contraceptive drugs can treat acne. Contraceptive drugs mainly contain estrogens, and estrogens include estrogen and progestin, two major categories. It is believed that androgens play a role in the development of acne. Female patients with moderate to severe acne who also have high androgen levels and high androgen activity such as seborrhea, acne, hirsutism, and androgenic alopecia should be treated with estrogen and progestin medications in a timely manner. Combined use of contraceptives may also be considered for female patients with late-onset acne and those whose acne worsens significantly before menstruation. The U.S. Food and Drug Administration (FDA) approves the use of birth control pills for the treatment of female acne patients aged >15 years. III. What is the therapeutic mechanism of contraceptive drugs? The mechanism of action of oral estrogen and progestin in the treatment of acne: 1. Estrogen: ① By reducing the excessive secretion of androgens caused by ovarian and adrenal cortical hyperfunction, and by stimulating the synthesis of sex hormone-binding globulin in the liver, the concentration of active estrogen in the serum is reduced, which plays a role in anti-sebum secretion. (2) Estrogen can increase the amount of sex hormone binding globulin synthesis and reduce the amount of free testosterone. (3) Estrogen has the effect of reducing the size of sebaceous glands and inhibiting lipid synthesis in sebaceous gland cells. 2. Progesterone: ① is a 5-alpha reductase inhibitor, which can reduce the amount of testosterone and dehydrotestosterone in plasma through negative feedback inhibition. ②It can inhibit the ability of sebaceous gland cells and keratin-forming cells to convert testosterone. ③Cyprogesterone acetate can also block the binding of sex hormones to their receptors. 3. Estrogen and progesterone can also act directly on hair follicle sebaceous glands to reduce sebum secretion and inhibit acne formation. Fourth, how to choose contraceptive pills? Oral contraceptives are a combination of estrogen and progestin, and their type selection is also very important. Some contraceptives contain sex hormone components, and certain synthetic progestins have cross-reactivity with androgen receptors, which can reduce the synthesis of sex hormone-binding globulin and increase the amount of free testosterone, thus aggravating or causing acne. Currently, the drugs often chosen for acne treatment are compounded cyclopentone acetate tablets (Daine-35, Diane35, each tablet contains 2mg of cyclopentone acetate + 35ug of ethinyl estradiol). 1 tablet is started on day 1 of the menstrual cycle for 21d, stopped for 7d, and repeated for 21d after another period, effective after 2-3 months of treatment for 3-4 months. For patients with particularly high seborrhea, the effect of conventional treatment with contraceptives is often not good. The efficacy can be significantly improved by taking 50-100mg of cyproterone acetate in addition to oral Daine-35 on 5-14d of the menstrual cycle. Adverse reactions include small amounts of uterine bleeding, breast distension, upper abdominal discomfort and facial skin redness, weight gain, deep vein thrombosis, and the appearance of chloasma.