Azelaic Acid

Azelaic acid is a naturally occurring dicarboxylic acid found in grains like wheat, rye, and barley. It is one of the few skincare actives with FDA-approved indications for both acne and rosacea, and one of even fewer considered safe during pregnancy. Its multi-action profile — brightening, antimicrobial, anti-inflammatory, and exfoliating — makes it uniquely versatile and exceptionally well-tolerated compared to other actives with similar efficacy.

How It Works

Azelaic acid works through several simultaneous mechanisms. For hyperpigmentation: it competitively inhibits tyrosinase, the rate-limiting enzyme in melanin synthesis, selectively reducing pigment production in hyperactive melanocytes without affecting normal melanocytes — this is why it's effective for melasma and post-inflammatory hyperpigmentation without the blanching risks of hydroquinone. For acne: it exerts direct bacteriostatic activity against Cutibacterium acnes (formerly Propionibacterium acnes) at concentrations achievable in topical formulations, and it normalizes keratinization in hair follicles — reducing the comedone formation that precedes acne. For rosacea: its anti-inflammatory mechanism involves inhibition of reactive oxygen species generation in neutrophils and reduction of pro-inflammatory cytokine release, directly targeting the vascular and inflammatory components of rosacea.

What the Research Shows

Azelaic acid has a three-decade clinical track record. For acne: a multicenter, double-blind study in the Journal of the American Academy of Dermatology compared 20% azelaic acid cream to 5% benzoyl peroxide across 289 patients over 20 weeks — equivalent inflammatory lesion reductions with fewer side effects. For rosacea: a randomized, double-blind, vehicle-controlled trial in the British Journal of Dermatology (2004) demonstrated that 15% azelaic acid gel significantly reduced papules, pustules, and erythema scores over 12 weeks — supporting its FDA approval for this indication. For hyperpigmentation: a double-blind study comparing 20% azelaic acid to 4% hydroquinone for melasma showed comparable efficacy at 24 weeks with fewer side effects and no rebound hyperpigmentation risk.

How To Use It

Over-the-counter formulations typically range from 10–15% azelaic acid; prescription formulations reach 15–20%. Apply to clean, dry skin — either as a spot treatment or all over the face and neck. Azelaic acid can be used morning and evening. A mild, transient tingling or flushing sensation upon application is normal, particularly in the first 2 weeks, and typically subsides with continued use. It does not increase photosensitivity, so morning use is fine — though SPF remains essential.