Anti-Androgen (mainly used for severe acne patients) Spironolactone selectively disrupts the cytochrome P450 enzyme system in the gonads and adrenal glands, inhibiting the activity of androgen-producing enzymes, thereby reducing androgen production. Also, spironolactone is a DHT receptor competition inhibitor, which reduces the binding of DHT to androgen receptor protein and decreases gene expression, resulting in reduced sebum production. Cimetidine can compete with DHT for androgen receptors, but does not affect serum androgen levels, and its anti-androgen effect is weaker than that of spironolactone. Norgestatin-destrol was the first low-dose oral contraceptive approved by the FDA for the treatment of acne and is mostly restricted to women. Glucocorticoids primarily inhibit adrenal and ovarian androgen production, and small doses of prednisone or dexamethasone have anti-inflammatory effects. Prednisone or dexamethasone have anti-inflammatory effects. Anti-abnormal keratinization of sebaceous ducts of hair follicles Retinoic acid is a group of compounds similar in structure to natural vitamin A. It regulates the growth and differentiation of epithelial cells and other cells, regulates immune and inflammatory processes, accelerates the shedding of epidermal keratin, keeps the skin dry, and is effective in moderate to severe acne. Retinoic acid has a keratolytic effect, which not only clears mature acne, but also inhibits microcomedema and improves the penetration of other combined anti-acne drugs. First-generation retinoic acid is a metabolite of natural retinoic acid, including all-trans retinoic acid, isotretinoic acid and retinoids. Isotretinoin is the drug of choice for severe acne or scarring acne that is not well treated with antibiotics]. The use of isotretinoin in pregnant women also poses a risk of malformed babies, so it is prohibited in pregnant women. Acne is the earliest lesion of acne, and after stopping retinoids, the number of microcomedones will rise again, leading to a recurrence of acne. Small doses of isotretinoin 0.04-0.11 mg/(kg?d) can prevent acne recurrence. The second-generation retinoic acid is a monoaromatic retinoic acid, including the aromatic derivatives of retinoic acid and aromatic esters. It is not as effective as the first generation in treating acne, and mainly treats severe psoriasis and ichthyosis. The third generation of retinoic acid is a polyaromatic retinoic acid, of which adapalene is a topical preparation that, if used consistently every day, will inhibit the formation of acne and even clear up severe acne within a few months. Adapalene increases the penetration of topical drugs such as antibiotics, shortens the course of treatment, and increases the effectiveness of treatment. Inhibiting the growth of microorganisms in the sebaceous gland units of hair follicles Antibiotics inhibit the chemotaxis of Propionibacterium acnes and neutrophils in hair follicles and reduce the concentration of free fatty acids in sebum, which can reduce the number of Propionibacterium acnes in the lesion area and significantly reduce inflammation. The main topical antibiotics used for acne are peroxymethylphenidate, erythromycin, clindamycin, tetracycline, etc. Oral anti-microbial therapy is mainly used for moderate to severe inflammatory acne, and tetracycline, erythromycin, minocycline, sulfonamides, etc. are commonly used. Phototherapy Studies have shown that the combined application of blue-red light is more effective than blue light alone. The mechanism of action may be a combination of both antibacterial and anti-inflammatory. Chinese herbal treatment Chinese herbal medicine has anti-acne bacilli, inhibits sebaceous gland secretion and hyperkeratosis of hair follicles, etc. The efficacy of Chinese herbal medicine in the treatment of acne is positive. The effectiveness of Chinese herbal medicine in the treatment of acne has been confirmed by the combination of internal and external treatment. Acne is a multifactorial skin disease with a long course and easy recurrence, and its pathogenesis is not yet fully understood. Although there are many treatment methods, there is a need to adopt a comprehensive approach and treat both internally and externally. In view of the self-limiting nature of acne, we should try to avoid the application of drugs with large side effects, and because acne is prone to pigmentation and scarring on the face, we should pay attention to the transformation of the medical model and the role of health education while focusing on medication. Daily care is also particularly important. The combination of Chinese and Western medicine is also an effective way to treat acne with Chinese characteristics.