Azelaic Acid —
Calmer Skin, Quieter Pigment

Azelaic acid (nonanedioic acid) is a dicarboxylic acid made naturally by the skin yeast Malassezia and also produced synthetically. It reduces acne bacteria, helps the pore lining shed normally and calms inflammation. It also slows tyrosinase, mainly in overactive pigment cells, so it can lighten melasma and post-acne marks without bleaching normal skin. Unlike retinoids, it does not make skin more sun-sensitive.

A Cochrane analysis found it better than placebo for acne, with low-to-moderate certainty. Randomised studies support a 15% gel for the red bumps of papulopustular rosacea. In melasma, 20% azelaic acid performed similarly to 4% hydroquinone in several studies of varying quality. Stinging and itching are the main side effects.

Medicated products contain 15–20%; lower-strength cosmetic products also exist. It is applied daily alongside sunscreen, and often layered with niacinamide, a gentle moisturiser or tranexamic acid; retinoids can be added with care. Results take months, and pigment changes more slowly than inflamed spots. It cannot shift deep dermal pigment such as Hori's naevus, and it does not replace sun protection.

• Anyone allergic to azelaic acid or its base should avoid it.
• Very sensitive skin or active eczema may find the early tingling uncomfortable.
• Rarely, lightening has been reported in darker skin; report any patchy change.
• In pregnancy or breastfeeding, discuss it with a doctor first.

Introduce one new active at a time and stop if irritation persists.

Azelaic acid creams and gels at medicated strengths (15–20%) are regulated as medicines, and the 20% cream is prescription-only. Lower-strength azelaic acid or its derivatives appear in some cosmetics; a doctor or pharmacist can confirm which category a product falls into.

It is used in acne treatment, for the bumps of rosacea, for post-inflammatory hyperpigmentation and in melasma maintenance, often after a course of hydroquinone.