A prescription treatment for acne, rosacea and dark marks at 15-20%. Cosmetic serums use about 10% or less, where it is much less studied.
Azelaic acid is a dicarboxylic acid made by yeasts that live on skin and found in grains. It kills acne bacteria, normalizes the way pore-lining cells shed, calms inflammation and slows overactive pigment cells. That mix makes it one of the few ingredients that address acne, rosacea bumps and post-acne marks at once.
The proven products are prescription: a 15% gel for rosacea and a 20% cream for acne and pigment. Over-the-counter serums typically contain 10% or less, or list azelaic acid low in the ingredients, so expect gentler and less certain results.
Prescription 15-20% azelaic acid is backed by multiple randomized trials; the 2024 US acne guideline gives it a conditional recommendation, and a Cochrane review found it probably works about as well as tretinoin but less well than benzoyl peroxide for acne. Evidence at the lower strengths used in cosmetics is sparse.
Reviews azelaic acid, usually as a 20% cream: in controlled studies it matched tretinoin, benzoyl peroxide, erythromycin and oral tetracycline for acne and was at least as effective as hydroquinone for melasma, with mostly mild, transient irritation.
49 trials (3,880 people): azelaic acid is probably less effective than benzoyl peroxide and about as effective as tretinoin for acne; evidence for salicylic acid, nicotinamide and alpha-hydroxy acids was low or very low quality, from small head-to-head trials, and no conclusions were reported for zinc or sulphur.
The American Academy of Dermatology's acne guideline makes strong recommendations for benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline, and conditional (lower-certainty) recommendations for topical salicylic acid, azelaic acid and clascoterone.