azelainsyre

Azelaic acid, sometimes written azelainsyre in some languages, is a naturally occurring saturated dicarboxylic acid with the chemical formula C9H16O4. It is classified as nonanedioic acid and occurs in grains such as barley, wheat, and rye. In the skin, azelaic acid can be produced by certain microbes, notably Malassezia species, and it is also manufactured synthetically for medical use.

Medical use and formulations: Azelaic acid is applied topically to treat mild-to-moderate acne vulgaris and rosacea, and it is used to address hyperpigmentary disorders such as melasma. Commercial products commonly come as 15% gel or 20% cream formulations, with regimens typically involving once or twice daily application to affected areas.

Mechanism of action: The acid has antimicrobial activity against Cutibacterium acnes and some fungi, and it exhibits anti-inflammatory effects by reducing keratinocyte proliferation and inflammatory mediators. It also inhibits the enzyme tyrosinase, contributing to depigmenting effects and improvement of hyperpigmentation.

Safety and considerations: Azelaic acid is generally well tolerated. Common adverse effects include mild burning, stinging, or dryness; less frequently irritation or contact dermatitis. Hypopigmentation can occur, especially in darker skin tones. Systemic absorption is low, and topical use is considered relatively safe during pregnancy when prescribed by a clinician. As with all topical therapies, users should follow product guidance and consult a clinician if irritation or unusual reactions occur.