Azelaic acid is a natural antibacterial and anti-inflammatory agent produced by skin yeast that is used to treat acne and rosacea. It works by inhibiting bacteria growth, facilitating skin renewal to reduce blemishes, and may help with hair growth by inhibiting the hormone DHT. Azelaic acid comes as a gel or cream applied morning and evening, though results and side effects like irritation vary between individuals. People with celiac disease should avoid it due to its wheat-derived components.