Azelaic Acid

Azelaic acid is a saturated dicarboxylic acid with nine carbon atoms and a carboxyl group at each end, formally named nonanedioic acid. ^[1] It occurs naturally in whole grains and is also generated by Malassezia furfur, a yeast that normally lives on human skin. ^[1] For commercial use it is typically manufactured by the ozonolysis of oleic acid, a fatty acid derived from vegetable oils.

In medicine it is used almost entirely on the skin. It is a well-established topical treatment for mild to moderate acne and for papulopustular rosacea, and it is used off-label for disorders of excess pigmentation such as melasma and post-inflammatory dark spots. ^[2] A systematic review of randomized trials found azelaic acid more effective than an inactive vehicle for rosacea, acne, and melasma, and broadly comparable to several standard comparator treatments. ^[2]

Reviews describe azelaic acid as a versatile agent with a favorable safety profile, effective either as a standalone treatment or in combination with other therapies. ^[3] Because it is minimally absorbed into the body, it is often regarded as one of the safer topical options, including during pregnancy, though medical advice should still be sought.

Its usefulness across different conditions reflects several distinct actions on the skin, including effects on acne-associated bacteria, on the way skin cells shed within pores, and on the pigment-producing enzyme tyrosinase. ^[1] This combination lets a single agent address the redness of rosacea, the clogged pores and bacteria of acne, and uneven pigmentation.

Azelaic acid is sold both as prescription-strength creams, gels, and foams and, at lower concentrations, in over-the-counter skincare products. It is applied directly to the skin, usually once or twice daily, and improvement typically takes several weeks of consistent use.

Azelaic acid is available by prescription and in lower strengths over the counter, and it is one of the better tolerated skin treatments. The usual side effects are temporary burning, stinging, itching, tingling, dryness, and redness where it is applied, which tend to settle as the skin adjusts. Rarely it can lighten skin more than intended, something to watch for in people with darker skin tones. It has very little whole body absorption and is generally regarded as safe to use during pregnancy and breastfeeding, unlike many other acne and pigment treatments.

The dermatological use of azelaic acid grew out of research in Italy in the 1970s by Marcella Nazzaro-Porro and Siro Passi, who were studying tinea versicolor and observed that the Malassezia yeast on skin produced dicarboxylic acids capable of inhibiting pigment production. That insight led them to develop azelaic acid as a treatment first for pigmentary disorders such as melasma and then for acne. It was subsequently commercialized as topical preparations, with a 20% cream (Azelex/Skinoren) reaching the U.S. market and a 15% gel (Finacea) later approved by the Food and Drug Administration in the early 2000s for rosacea. The molecule itself is a naturally occurring nine-carbon dicarboxylic acid also found in cereal grains.

Azelaic acid is well liked in dermatology as a versatile, gentle multitasker, praised for treating acne, rosacea, and hyperpigmentation through a single ingredient with a favorable tolerability profile. It is often recommended for sensitive skin and, notably, is considered a safe option during pregnancy, which sets it apart from many other acne and pigment treatments. Network meta-analyses of papulopustular rosacea rank it among the effective topical therapies. Its reputation for calming redness while fading dark marks has made it a favorite in both prescription and cosmeceutical routines.