azelaic acid + glycolic acid

Azelaic acid + glycolic acid is a topical combination therapy used primarily in dermatology for the treatment of facial hyperpigmentation (such as melasma) and mild-to-moderate acne. Azelaic acid is a dicarboxylic acid with anti-inflammatory, antibacterial, comedolytic, and tyrosinase-inhibiting properties, making it effective against acne and hyperpigmentation by reducing inflammation, inhibiting melanin production, and normalizing keratinization[7][8]. Glycolic acid is an alpha hydroxy acid (AHA) that acts as a chemical exfoliant by breaking down the bonds between dead skin cells on the surface of the skin, promoting cell turnover and improving texture[3][10]. When combined, glycolic acid enhances penetration of azelaic acid by exfoliating the stratum corneum. Clinical studies have shown that this combination is at least as effective as hydroquinone or tretinoin for treating hyperpigmentation in darker-skinned patients and mild-to-moderate acne while offering superior tolerability compared to tretinoin[1][6]. The combination may cause mild local irritation such as peeling or dryness but generally has a favorable safety profile.