Azelaic acid

What it is

Azelaic acid is a dicarboxylic acid found naturally in grains such as barley, wheat and rye. It is also made by Malassezia, a yeast that lives on normal skin¹. At 15 to 20% it is a prescription medicine, sold as a cream, gel or foam^{1, 4}; 10% versions are available over the counter as serums and creams. Few actives work on acne, rosacea and dark marks at once.

What the evidence says

Evidence: strong for acne and papulopustular rosacea at 15 to 20%; moderate for melasma and post-inflammatory dark marks; the 10% over-the-counter strength is less studied and works more slowly.

Azelaic acid reduces the bacteria in pores, slows the abnormal shedding of cells that blocks them, and dampens inflammation by mopping up free radicals¹. In controlled trials, 20% cream matched tretinoin, benzoyl peroxide and erythromycin for acne, and was at least as effective as hydroquinone for melasma². A 15% gel is approved for rosacea in the United States and for acne and rosacea in several European countries¹. In a small open trial of 29 women, 20% azelaic acid reduced melasma scores more than 4% hydroquinone after two months³, and dermatologists value it for the brown marks acne leaves in darker skin¹. It is not a bleaching agent, so it suits melanin-rich skin and rosacea-prone skin. Acne usually improves after about four weeks, with full benefit by six months; rosacea can take twelve weeks¹.

How people use it

• Prescription 15 to 20% products: use exactly as your prescriber and the patient leaflet direct⁴.
• Over-the-counter 10% serum or cream once or twice daily for a milder start.
• Layer moisturiser over it if it stings. Keep it away from your eyes and mouth⁴.
• Daily sunscreen is part of the treatment for dark marks; see dark spots and hyperpigmentation.

Cautions

• Itching, burning, stinging, tingling and dryness are common in the first weeks and usually fade⁴. Starting once daily helps.
• It can lighten the skin where it is applied, which shows more on dark complexions^{1, 4}. Apply it evenly rather than only on spots.
• Pregnancy: the American Academy of Dermatology describes azelaic acid as thought to be safe in pregnancy, based on animal studies, and advises getting expert advice before using any acne treatment while pregnant⁵. Check with your own doctor or midwife.
• Tell your prescriber if you have asthma or recurrent cold sores⁴. Stop and seek advice for severe redness or scaling¹; see when to see a dermatologist.