What is azelaic acid and what does it treat?

Azelaic acid is a naturally occurring dicarboxylic acid found in grains that has antimicrobial, anti-inflammatory, and melanin-inhibiting properties. It effectively treats acne, rosacea, and hyperpigmentation including melasma, making it unusually versatile. It is available at 10% concentration over the counter and 15–20% by prescription. Unlike retinol or AHAs, azelaic acid is considered safe during pregnancy and is well-tolerated by sensitive skin.