Azelaic Acid

Also known as: Finacea (brand), Azelex (brand), dicarboxylic acid

Hair RestoreDermatology

In plain English

Azelaic acid is a skin treatment for acne, rosacea, and dark spots (melasma/post-inflammatory pigmentation). It calms inflammation, reduces acne bacteria, unclogs pores, and gently fades excess pigment. It is well tolerated and considered safe in pregnancy, which makes it a useful option when retinoids can't be used. In hair formulas it is added in small amounts for its anti-inflammatory and mild anti-androgen effects.

The science

Azelaic acid is a naturally occurring C9 dicarboxylic acid with antibacterial (against Cutibacterium acnes), anti-inflammatory (inhibits kallikrein-5/cathelicidin and reactive oxygen species), anti-keratinizing, and tyrosinase-inhibiting (depigmenting) activity. It is FDA-approved as 15% gel for rosacea and 20% cream for acne; across indications, 15-20% formulations produce clinically meaningful improvement with efficacy in rosacea comparable to metronidazole and in melasma comparable to hydroquinone.

References

• Azelaic acid in dermatology: a review of its mechanism of action, 2025
• van Zuuren EJ et al., Cochrane Database Syst Rev 2015 (interventions for rosacea)