Azelaic Acid for Acne: Evidence, Dark Marks and Pregnancy Safety

Azelaic acid is a gentle, multi-tasking acne treatment: it helps unclog pores, reduces acne bacteria and inflammation, and can fade the dark marks that spots leave behind. Most of the evidence is for prescription 15% and 20% strengths, and the 2024 AAD guideline recommends it conditionally. It’s also one of the few acne treatments generally considered safe in pregnancy, which is a big reason people seek it out.

What is azelaic acid?

Azelaic acid is a naturally occurring dicarboxylic acid. In the US it’s available by prescription as a 20% cream that is indicated for mild-to-moderate inflammatory acne, and as a 15% gel whose US label is for the papules and pustules of mild to moderate rosacea (the 15% gel has also been studied in acne). According to DermNet, it’s used for acne, rosacea, post-inflammatory hyperpigmentation and melasma, and is “particularly useful for darker skinned patients.”

Prescription vs over-the-counter azelaic acid

Azelaic acid is not one of the active ingredients allowed in the FDA’s OTC acne drug monograph (those are benzoyl peroxide, salicylic acid, sulfur and resorcinol). The non-prescription azelaic acid serums and creams you see in shops are skincare products at lower strengths than the prescription versions. They may still help some people, but almost all the clinical trial data are for 15% and 20% formulations, so you can’t assume a lower-strength product will perform the same.

How does azelaic acid work?

It acts on several parts of acne at once. An overview of European trials describes azelaic acid as antikeratinizing (it reduces pore-clogging), antibacterial and anti-inflammatory. The FDA label for the 20% cream notes antimicrobial activity against acne bacteria and a normalizing effect on keratinization that reduces microcomedo formation, although it says the exact mechanism is not fully understood.

It also affects pigment. A 2024 randomized trial explains that azelaic acid impedes tyrosinase activity (a key enzyme in melanin production) and acts on overactive pigment cells, which is why it’s used for dark marks.

What does the evidence show for acne?

The 2024 AAD guideline gives azelaic acid a conditional recommendation. According to MDedge’s guideline coverage, that recommendation rests on three randomized trials rated moderate certainty, and the guideline notes azelaic acid may be “particularly helpful for patients with sensitive skin or darker skin types” because of its effect on dyspigmentation.

• In a double-blind trial of 60 people with mild to moderate acne, 20% azelaic acid gel reduced total lesion count by 60.6% over 45 days, versus 19.9% with a placebo gel; acne severity scores fell 65.2% versus 21.3%.
• An overview of European trials of the 20% cream reported overall efficacy comparable to tretinoin 0.05%, benzoyl peroxide 5% and topical erythromycin 2% in mild to moderate acne, and noted that it doesn’t induce resistance in acne bacteria. This is older (1996) evidence.
• In the 2021 network meta-analysis of topical treatments, azelaic acid data were only available for lesion counts, and confidence in its estimate was rated very low.

The honest summary: azelaic acid works better than a placebo and seems to hold its own against older standard treatments, but the trials are fewer and smaller than those for retinoids and benzoyl peroxide. The NHS says you’ll usually need to use it for a month before your acne improves, and DermNet says maximum results may take six months of continuous use.

Can azelaic acid fade dark marks (PIH)?

This is where azelaic acid stands out. Post-inflammatory hyperpigmentation (PIH) is the brown or dark mark left after a spot heals, and it’s especially common and persistent in darker skin. The AAD’s patient guide says azelaic acid “fights acne and can also fade the dark spots that appear when an acne spot clears.”

• A 2024 randomized, double-blind, placebo-controlled trial in China (60 people completed, 12 weeks) found 15% azelaic acid gel reduced both red marks (post-inflammatory erythema) and brown marks (PIH) more than placebo, with measurably lower melanin in treated PIH at week 12.
• A 16-week pilot study of 20 adults with Fitzpatrick skin types IV to VI found 15% gel twice daily reduced both acne lesions and PIH. With no control group, it’s weaker evidence.

If dark marks bother you more than active spots, see acne scars vs dark spots for how to tell marks from true scars.

How to use azelaic acid

• Frequency: the 20% cream label directs use twice daily, in the morning and evening. If you’re sensitive, ask your prescriber whether starting once a day is reasonable.
• Sun: the NHS notes it does not make your skin sensitive to sunlight, so you don’t have to avoid sun exposure the way you might with some other acne treatments.
• Combining: guidelines favor combining treatments with different mechanisms. The NICE-based pathway summarized by NHS Scotland lists topical azelaic acid alongside an oral antibiotic as an option for moderate to severe acne.
• Patience: expect to wait at least a month for improvement. The 20% cream label says improvement occurs in the majority of patients with inflammatory lesions within four weeks.

It can also be a good fit in an adult hormonal acne routine if your skin doesn’t tolerate retinoids well.

Azelaic acid vs benzoyl peroxide and adapalene

On the strength of evidence, azelaic acid sits a step below benzoyl peroxide and topical retinoids, both of which get strong recommendations in the 2024 AAD guideline. Where it earns its place is in the trade-offs. It doesn’t cause sun sensitivity, according to DermNet; it’s generally considered acceptable in pregnancy, unlike retinoids; and it also treats dark marks. That makes it a sensible option if retinoids irritate you, if you’re pregnant, or if post-acne marks are your main concern. For the stronger-evidence options, see benzoyl peroxide for acne and adapalene (Differin).

Side effects and who should be careful

Stinging and itching are the main complaints. The 20% cream label reports pruritus, burning, stinging and tingling in approximately 1% to 5% of patients, with redness, dryness, peeling and irritation in under 1%. In one recent trial it was much more common: in the 2024 trial, 66.67% of people reported mild redness, tingling, dryness, itching or peeling early on, which settled within about a week with a short break and moisturizer. DermNet notes people with very sensitive skin or eczema may find it irritating.

One caution for darker skin: the label reports isolated cases of hypopigmentation (lightening) and advises monitoring people with darker complexions for early signs. The AAD’s guideline summary likewise notes azelaic acid may cause dyspigmentation or irritation in some patients.

Is azelaic acid safe in pregnancy?

It’s one of the acne treatments generally considered acceptable. The AAD says azelaic acid “is thought to be safe to use during pregnancy,” noting that animal studies haven’t shown birth defects. The MotherToBaby fact sheet notes the American College of Obstetricians and Gynecologists lists azelaic acid among topical acne options that may be used in pregnancy.

The prescription label is more guarded, as drug labels usually are. It reports that about 4% of applied azelaic acid is absorbed into the body, that no teratogenic effects were seen in animal studies, and that because there are no adequate human studies it should be used in pregnancy only if clearly needed. The AAD also listed azelaic acid among alternatives for people concerned about benzoyl peroxide. Always check with your obstetrician or dermatologist before starting it.

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