Azelaic Acid: What It Treats, What the Evidence Shows, and How to Use It
Azelaic acid is having a moment, and it deserves it. It is one of the few skincare ingredients that works on redness, breakouts and uneven pigmentation at the same time, and unlike many trending actives it has a large body of clinical trials behind it. Here is what those trials actually show.
What is azelaic acid?
Azelaic acid is a naturally occurring acid that is also made synthetically for skincare. It is used as a topical treatment for acne and rosacea, and has been studied for pigmentation such as melasma. Whatever you use it for, daily sunscreen is still essential.
What the evidence shows
A 2023 systematic review in the Journal of Cosmetic Dermatology pulled together 43 randomised controlled trials of topical azelaic acid lasting at least six weeks. Its findings, by condition:
Rosacea (20 studies)
After 12 weeks, azelaic acid improved redness (erythema) severity, inflammatory lesion counts, overall improvement and treatment success compared with an inactive vehicle. It was also more effective than metronidazole 0.75% for erythema severity, overall improvement and inflammatory lesions.
Acne (16 studies)
Azelaic acid was more effective than vehicle for global assessments and for reducing acne severity. At 20%, it reduced more lesions than erythromycin gel.
Melasma and hyperpigmentation (7 studies)
Azelaic acid 20% was significantly better than vehicle for both severity and global improvement, and better than hydroquinone 2% for global improvement.
Skin ageing
The review found no eligible randomised trials evaluating azelaic acid for skin ageing, so claims that it is an anti-ageing ingredient are not backed by that evidence.
The reviewers also reported very few significant differences in commonly reported side effects between azelaic acid and its comparators, and concluded that where it matches other treatments it may be a good option in some clinical situations.
Note on strengths: the erythromycin comparison in acne and the melasma comparisons above refer to 20% azelaic acid. Many over-the-counter products are lower strength, so do not assume a cosmetic serum will behave like the products studied. Higher-strength azelaic acid is typically available on prescription, so ask a pharmacist or doctor if you want to try it.
How to use azelaic acid
- Apply to clean, dry skin after cleansing and before moisturiser.
- Start once a day (morning or evening), then build to twice daily if your skin is comfortable.
- Expect some tingling. Mild stinging, itching or dryness is the most common complaint, usually early on. If it is more than mild, or does not settle, stop and speak to a pharmacist or doctor.
- Be patient. The rosacea results above were measured at 12 weeks, and the included trials lasted at least six.
- Wear sunscreen every morning. Pigmentation in particular is hard to improve if the sun keeps re-triggering it. See our SPF guide.
What to pair it with
These are general routine tips rather than findings from the review:
- Niacinamide is a popular partner for redness and barrier support. See our niacinamide guide.
- Retinol or strong exfoliants: if your skin is reactive, avoid starting everything at once. Introduce one active at a time, and consider alternating nights.
- A simple moisturiser helps if you notice dryness. If your skin feels raw, see our guide to the signs of a damaged barrier.
Azelaic acid in pregnancy
Azelaic acid is commonly suggested as an alternative to retinoids during pregnancy, and our pregnancy skincare guide covers it. As with any treatment in pregnancy or while breastfeeding, check with your midwife or doctor first.
Azelaic acid for hormonal breakouts
If your breakouts follow your cycle, azelaic acid is one of several options covered in our hormonal acne guide. It treats the inflammation and the marks that follow, but it does not change underlying hormones.
The bottom line
Azelaic acid is not just a trend. A review of 43 randomised trials found it more effective than vehicle for rosacea, acne and melasma, often matching established treatments. Its limits are just as clear: there is no trial evidence for skin ageing, and the strongest results used higher strengths than many cosmetic products contain. If redness, breakouts or dark marks are your main concerns, it is well worth a conversation with a pharmacist or dermatologist.
Frequently Asked Questions
What does azelaic acid do for skin?
A systematic review of 43 randomised trials found topical azelaic acid more effective than vehicle for rosacea, acne and melasma, with some comparisons showing it matched or beat other treatments.
Does azelaic acid work for dark spots?
In seven melasma studies, azelaic acid 20% was significantly better than vehicle and better than hydroquinone 2% for global improvement. Results were studied in melasma specifically.
Is azelaic acid anti-ageing?
The review found no eligible randomised trials evaluating azelaic acid for skin ageing, so the evidence does not currently support that claim.
How long does azelaic acid take to work?
Included trials lasted at least six weeks, and the rosacea benefits in the review were measured at 12 weeks. Allow at least a few weeks before judging it.
Can I use azelaic acid every day?
Many people use it once or twice daily, building up gradually. Mild tingling or dryness is the most common side effect; if irritation is more than mild, stop and ask a pharmacist or doctor.
Sources
- King S, et al. A systematic review to evaluate the efficacy of azelaic acid in the management of acne, rosacea, melasma and skin aging. J Cosmet Dermatol, 2023. doi:10.1111/jocd.15923
This article is general information, not medical advice. If you have a skin or scalp condition, or you are pregnant, breastfeeding or taking medication, speak to a doctor, pharmacist or dermatologist before changing your routine.
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