15% Azelaic Acid Cream is available over the counter. Azelaic acid is a natural saturated dicarboxylic acid for the topical treatment of mild and moderate inflammatory acne vulgaris. It has many pharmacological uses in dermatology, including antibacterial, antikeratinizing, sebaceous gland regulation, tyrosinase inhibition and other properties, as follows. 1. Antibacterial: azelaic acid is also an antibacterial agent, which can quickly enter the cell and inhibit the protein synthesis of bacteria, and has an inhibitory and killing effect on bacteria. 2. Anti-keratinization: It has anti-keratinization effect on normal skin and acne-infected skin, and can prevent excessive keratinization of hair follicles. 3. Regulation of sebaceous glands: It can inhibit the conversion of excessive androgens into dihydrotestosterone, which ultimately inhibits excessive sebaceous gland secretion. 4. Inhibition of tyrosinase: competitive inhibition of tyrosinase in hyperfunctional melanocytes, reducing pigment synthesis, but does not inhibit pigment synthesis in normal pigment cells. 15% azelaic acid is the drug of choice for the treatment of persistent facial erythema and papules and pustules of rosacea, and is generally more effective in the adjuvant treatment of acne. A small percentage of patients experience itching, burning and stinging sensations at the beginning of the medication, but these are generally mild and transient. The medication should be used as directed by a physician.