Azelaic acid explained: acne, redness and dark marks, and what the prescription labels say
Azelaic acid rarely gets the attention of retinoids or vitamin C, partly because it does nothing dramatic. It does several useful things at once, and it does them with less irritation than most acne treatments: it works on spots, calms the red bumps of rosacea, and is widely used on the dark marks that acne leaves behind. It is also one of the few actives where the strongest versions come with a full official label, which makes it easier than usual to say what is known and what is not.
- Azelaic acid is a naturally occurring dicarboxylic acid, found in grains and also made by a yeast that lives on normal skin. Skincare uses an industrially made version.
- In the US, a 20% cream is approved on prescription for mild to moderate inflammatory acne, and a 15% gel for the papules and pustules of mild to moderate rosacea.
- The usual side effect is itching, burning or stinging at the start, which often settles with continued use.
- The labels ask people with darker skin to watch for light patches, which have been reported rarely.
What azelaic acid is
Chemically, azelaic acid is a saturated acid with nine carbon atoms and an acid group at each end. It occurs in wheat, rye and barley, and Malassezia, a yeast that is a normal resident of human skin, produces it too. The powder used in creams and gels is made industrially, from oleic acid, a fatty acid found in many plant oils.
It is not an AHA or a BHA, and it does not work mainly by dissolving the bonds between dead skin cells the way glycolic or salicylic acid do. It is poorly soluble in water, which is why many azelaic acid products feel slightly gritty or chalky, and why it usually comes as a cream, gel or suspension rather than a clear toner.
How it works
The prescription labels are frank that the exact mechanism is not known. What laboratory and biopsy studies show is a combination of effects that suit acne-prone skin:
- Antibacterial activity against Cutibacterium acnes (formerly Propionibacterium acnes), the bacterium involved in inflamed spots, and against Staphylococcus epidermidis.
- Normalising keratinisation: in skin treated with the 20% cream, the outer layer was thinner and showed fewer of the structures involved in the build-up that blocks pores. That points to fewer microcomedones, the tiny blockages from which spots grow.
- Calming inflammation, which is the reason it is used for rosacea bumps.
- Slowing tyrosinase, an enzyme the skin uses to make pigment. This is the basis for its use on dark marks after spots and on uneven pigmentation, a use that is common in dermatology but is not one of the indications on the US labels.
| Product type | Strength | Approved use |
|---|---|---|
| Cream | 20% | Topical treatment of mild to moderate inflammatory acne vulgaris |
| Gel | 15% | Inflammatory papules and pustules of mild to moderate rosacea |
Cosmetic products sold without a prescription contain azelaic acid at lower strengths, and some use related ingredients with similar-sounding names, such as derivatives designed to dissolve more easily. Rules on strength and claims differ between countries, and a "booster" or "suspension" sold online is not the same product as the prescription cream your doctor might suggest. The ingredient list tells you whether you are getting azelaic acid itself; the percentage, if the brand does not print it, you usually cannot know.
What it is good for
Inflammatory acne. On the 20% cream's label, most patients with inflamed spots saw improvement within four weeks, used twice a day. The label also tells patients to keep using it for the full prescribed treatment period.
Rosacea bumps. The 15% gel is approved for the papules and pustules of rosacea. Its label notes that it has not been evaluated for redness alone, without bumps: if your rosacea is mainly flushing and visible vessels, azelaic acid may not be the answer.
Dark marks. The brown or purple marks that linger after spots, more noticeable on medium and darker skin, are a common reason people reach for azelaic acid. Here sunscreen does at least half of the work: marks fade more slowly on skin that keeps getting UV.
If your skin is oily and congested with blackheads rather than inflamed, salicylic acid is usually the more direct tool. The two can share a routine, on different evenings at first.
The tingle, and who should go carefully
Azelaic acid is acidic, and the most common complaints on the US labels are itching, burning, stinging and tingling, especially on broken or inflamed skin and at the start of treatment. The acne cream's label says this commonly subsides if treatment continues. Dryness, peeling and redness are less frequent. A tingle that fades within minutes is normal; burning that lasts, swelling or a spreading rash is a reason to stop and seek advice.
- Darker skin tones. There have been isolated reports of hypopigmentation, light patches, after azelaic acid. Because it was not well studied in people with dark complexions, the labels ask them to watch for early changes in skin colour and report them.
- Sensitive or reactive skin. Try it on a small area first; our guide to patch testing at home sets out how.
- Pregnancy and breastfeeding. Only a small fraction of a dose applied to the skin is absorbed into the body, according to the label. The labels also state that there are no adequate, well-controlled studies in pregnant women, so this is a decision to make with your doctor or midwife.
- Children. Safety and effectiveness have not been established under 12 years of age for the acne cream.
- Asthma and cold sores. Rare reports include worsening of asthma and flare-ups of cold sores in people prone to them.
Fitting it into a routine
- Apply to clean, dry skin. The labels describe a thin film massaged in after washing and patting the skin dry, then washing your hands. Keep it away from the eyes, mouth and inside of the nose.
- Start once a day. Prescription products are used twice daily, but with a cosmetic version or sensitive skin, evening only for the first two weeks is a gentler start.
- Moisturise after it if your skin feels tight. A plain, fragrance-free moisturizer is ideal, as in our routine for sensitive skin.
- Do not stack it with every other active at once. Azelaic acid is relatively easy to combine, but adding it to a retinoid, an exfoliating acid and vitamin C in the same week is a reliable way to irritate your skin. Our guide to combining active ingredients has a weekly schedule.
- Wear sunscreen every morning, particularly if you are treating marks.
- Judge it after a couple of months, not a couple of days. If spots are still inflamed and spreading by then, or leave scars, see a doctor: prescription combinations work better than adding more products.
In a hot, humid climate, a light gel texture is often easier to wear than a cream, and the slightly powdery finish of many azelaic acid products sits well under sunscreen. Whichever you choose, consistency matters more than strength.
Sources
- US National Library of Medicine, DailyMed, "Azelex (azelaic acid) cream, 20%", prescribing information: indication, clinical pharmacology, precautions and adverse reactions.
- US National Library of Medicine, DailyMed, "Finacea (azelaic acid) gel, 15%", prescribing information: indication in rosacea, pregnancy and precautions.
- Natural occurrence, production from oleic acid, and tyrosinase inhibition: Wikipedia, "Azelaic acid".
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