How azelaic acid works
Three mechanisms: (1) Anti-acne: inhibits Cutibacterium acnes growth via disruption of cellular proteins — without antibiotic resistance risk. (2) Anti-pigmentation: inhibits tyrosinase (the enzyme that catalyses melanin synthesis) selectively in hyperactive melanocytes, without affecting normally-pigmented skin. (3) Anti-inflammatory: reduces prostaglandin synthesis and keratinocyte activation, directly addressing rosacea pathophysiology. No other single OTC ingredient achieves all three simultaneously.