Azelaic acid

Also known as: Finacea, Azelex, nonanedioic acid

Azelaic acid is a dicarboxylic acid originally derived from grains, available as prescription 15 to 20% formulations and OTC around 10%. It is one of the quiet overachievers in dermatology: a 2020 Cochrane review rated its acne evidence moderate quality (better than salicylic acid or niacinamide), a 2024 network meta-analysis found 20% azelaic acid had the largest effect among topicals for papulopustular rosacea, and meta-analysis suggests it can match or beat hydroquinone for melasma. It is also one of the few actives considered safe in pregnancy.

How it works

Azelaic acid kills acne bacteria, normalizes the shedding of cells that clog pores, and calms inflammation by damping reactive oxygen species. Separately, it inhibits tyrosinase and is selectively toxic to overactive pigment cells, which is why it lightens dark patches without bleaching normal skin.

What the evidence says, claim by claim

These are the results measured in studies, not the results shown in ads. Where the research is weak, the grade says so.

For acne

Strong evidence

The 2020 Cochrane review (49 trials, 3,880 participants across the covered agents) found azelaic acid was the topical with moderate-quality supporting evidence, and a 2023 systematic review found lesion reductions comparable to topical retinoids with better tolerability in some trials. Typical courses run 12 weeks at 15 to 20%.

Multiple randomized controlled trials or a meta-analysis support this use. The effect is real and repeatable.

Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne (Cochrane Database of Systematic Reviews, 2020; systematic-review)
A systematic review to evaluate the efficacy of azelaic acid in the management of acne, rosacea, melasma and skin aging (Journal of Cosmetic Dermatology, 2023; systematic-review)

For rosacea and redness

Strong evidence

A 2024 network meta-analysis of 19 RCTs with 8,208 participants found azelaic acid 20% had the largest effect on investigator-rated improvement in moderate-to-severe papulopustular rosacea (odds ratio 8.54, 95% CI 2.48 to 29.45), ranking above metronidazole and ivermectin. Meta-analyses within a 2023 review of 20 rosacea studies found significant improvements in erythema and inflammatory lesions versus vehicle at 12 weeks. Note it treats bumps and associated redness, not flushing or visible vessels.

Multiple randomized controlled trials or a meta-analysis support this use. The effect is real and repeatable.

The efficacy and safety of minocycline, metronidazole, ivermectin, and azelaic acid in moderate-to-severe papulopustular rosacea: A systematic review and network meta-analysis (JAAD International, 2024; meta-analysis)
A systematic review to evaluate the efficacy of azelaic acid in the management of acne, rosacea, melasma and skin aging (Journal of Cosmetic Dermatology, 2023; systematic-review)

For melasma

Moderate evidence

A 2023 meta-analysis of 6 RCTs with 673 melasma patients found azelaic acid may reduce melasma severity (MASI score) more than hydroquinone, with no difference in side effects. Individual trials used 20% cream over 8 to 24 weeks. The trials are older and of mixed quality, which keeps this at moderate rather than strong.

Randomized trials support this use, but they are few, small, or short. The effect is probably real. The size of it is less certain.

Azelaic Acid Versus Hydroquinone for Managing Patients With Melasma: Systematic Review and Meta-Analysis of Randomized Controlled Trials (Cureus, 2023; meta-analysis)
Efficacy and safety of topical agents in the treatment of melasma: What's evidence? A systematic review and meta-analysis (Journal of Cosmetic Dermatology, 2023; meta-analysis)

Risks and what can go wrong

Mild, transient burning, stinging, and itching in the first weeks are common; the rosacea network meta-analysis found azelaic acid 15% had significantly higher odds of (mostly mild) adverse events than comparators. No bleaching of normal skin, no sun sensitivity, and it is widely considered safe during pregnancy and breastfeeding, which makes it the go-to for pregnancy melasma and acne.

The practical details

Prescription at 15% gel or foam (Finacea) and 20% cream (Azelex) in the US; 10% versions are OTC in many countries. Applied twice daily; expect 4 to 12 weeks for visible results. The gritty texture of some formulations is normal. Often combined with retinoids or used where hydroquinone is unsuitable.