What does azelaic acid do for skin?

Last updated: October 2026

Azelaic acid is a nine-carbon dicarboxylic acid that occurs naturally in grains such as wheat, rye and barley. On skin it has antibacterial, anti-keratinizing, anti-inflammatory and antimelanogenic activity, which is why it is used for acne, the bumps and redness of rosacea, and uneven pigment such as melasma. In the United States, 15% gel and foam and 20% cream are prescription drugs.

What is azelaic acid?

Azelaic acid (1,7-heptanedicarboxylic acid) is a saturated dicarboxylic acid with nine carbon atoms^3,5. It occurs in grains such as rye, wheat and barley, and the human body makes small amounts from fatty acids⁴. US prescription labeling describes it as a dietary constituent of whole grain cereals and animal products³.

Its use on skin began with an observation about pigment⁴. In the 1970s, researchers studying the pale patches of pityriasis versicolor found that the skin yeast Malassezia furfur breaks down fatty acids into dicarboxylic acids, including azelaic acid, that inhibit melanocytes⁴.

Today it appears in both prescription drugs and cosmetic formulas⁵. A 2023 review counted commercially available gels and creams with cosmetic or drug status containing 5% to 20% azelaic acid⁵.

How does azelaic acid work on skin?

Laboratory and clinical research describes several actions at once⁴:

• Antibacterial: it crosses the bacterial cell membrane and lowers the internal pH of bacteria such as Cutibacterium acnes (formerly Propionibacterium acnes), and a 2024 review reports that, unlike antibiotics, it does not induce bacterial resistance⁴.
• Anti-keratinizing: it reduces the excess build-up of skin cells inside and around follicles, the process that contributes to clogged pores⁴.
• Antimelanogenic: it competitively inhibits tyrosinase, the enzyme that starts melanin production, and suppresses the proliferation of melanocytes⁴.
• Anti-inflammatory: it inhibits the release of reactive oxygen species from neutrophils and suppresses TLR2, the enzyme KLK5 and the peptide LL-37, a pathway linked to rosacea⁴.

What is azelaic acid used for, and how strong is the evidence?

The evidence is deepest for acne and papulopustular rosacea, the two uses that US regulators have reviewed as prescription indications^1,3. Pigment uses rest on smaller trials⁶.

Regulatory labeling is more cautious about mechanism than the reviews: the US label for 15% foam states that the mechanisms by which azelaic acid acts in rosacea are unknown, and the 20% cream label states that the exact mechanism is not known^2,3.

Does azelaic acid help rosacea?

Yes, for the bumps and pustules of papulopustular rosacea. FDA approved Finacea, an azelaic acid 15% gel, in December 2002 with a prescription marketing status¹. The 15% foam is labeled for the inflammatory papules and pustules of mild to moderate rosacea².

On redness specifically, a placebo-controlled study found 15% gel reduced erythema and inflammation more than placebo gel, and two studies found 15% azelaic acid more effective than metronidazole gel at reducing inflammatory lesions and erythema⁵.

A 2025 network meta-analysis of 19 randomized trials with 8,208 participants with moderate to severe papulopustular rosacea ranked azelaic acid 20% highest for improvement in investigator global assessment, found 15% comparable to metronidazole 0.75% and ivermectin 1%, and found that 15% carried the highest odds of adverse events among the agents compared⁷. Rosacea is a diagnosis, so the choice of prescription therapy belongs with a dermatologist or other clinician.

Is azelaic acid a prescription drug or a cosmetic ingredient?

It can be either, depending on the product's intended use. Under US law, whether a product is a cosmetic or a drug is determined by its intended use, and a product making a drug claim is regulated as a drug⁸.

Drugs@FDA lists Finacea 15% gel with a prescription marketing status¹, and the 15% foam and 20% cream carry prescription drug labeling^2,3. Cosmetic formulas sit alongside them on the market: products with cosmetic or drug status contain 5% to 20% azelaic acid⁵.

FDA also notes that the law does not recognize the term cosmeceutical, and that a product can be a drug, a cosmetic or both⁸. Claims stated on the labeling are one of the ways intended use is established, so the label tells you which category you are holding⁸.

How do you use azelaic acid, and what side effects should you expect?

With a prescription product, follow the prescriber's directions and the label. With a cosmetic product, follow the product directions, and on reactive skin, a patch test before full use shows how your skin responds.

The most common reactions are local. In US labeling, 15% foam lists local site pain (6.2%), itching (2.5%), dryness (0.7%) and redness (0.7%) as the most common adverse reactions², and 20% cream lists itching, burning, stinging and tingling in roughly 1% to 5% of patients³. A 2023 review describes side effects as generally mild and transient local irritation⁵.

Both labels report hypopigmentation after azelaic acid use, and the foam label notes that azelaic acid has been reported to irritate the eyes, so keep it away from the eye area^2,3.