Ingredient glossary
Azelaic Acid
On your shelf ✓What Azelaic Acid does for your skin, who it suits, and what to watch for.
INCI: Azelaic Acid
In short: Azelaic Acid delivers anti acne and brightening, suits most skin types, and the evidence behind it is moderate. One thing to know: introduce it gently.
- What it does
- Anti acne, brightening
- Best for
- Combination, Oily, Sensitive skin
- Watch out
- Introduce it gently
- Evidence
- Moderate
- How long
- 8–12 weeks
how it was measured
Measured on inflammatory lesion count (papules and pustules) in papulopustular rosacea, investigator-counted; measured at the trial's end, so possibly sooner.PMID 12789172PMID 30585305PMID 38300170
The molecule
The Glow take
One of the ingredients I trust most.
When your goal is calming breakouts and congestion, Azelaic Acid delivers, with a solid amount of evidence behind it. Introduce it gently, and pair it with something soothing if your skin runs sensitive.
— Maya
What it does
- anti acne
- brightening
- anti redness
moderate evidenceThe trials all sit at prescription strength, 15% or 20%: a systematic review found high-certainty evidence that 15% gel or 20% cream reduces rosacea papules and…
Why we say this
- The trials all sit at prescription strength, 15% or 20%: a systematic review found high-certainty evidence that 15% gel or 20% cream reduces rosacea papules and pustules, the 2024 US acne guideline rates it only a conditional option for acne, and the pigment studies in Fitzpatrick IV–VI skin used 20% cream.
- The 10% sold over the counter has not been tested this way.
- Burning or stinging in the first weeks is the usual complaint, in roughly 5 to 10 percent of users, and it settles.
On a label: works best above 10%.
The dicarboxylic acid family, at a glance
2 dicarboxylic acid entries in the base, Azelaic Acid among them. 1 of the 2 is a hero active.
- Succinic Acid118 Da
- Azelaic Acid188 Da
How much do you need?
15%+
The vehicle-controlled trials worked from 15%; no published dose comparison sets a ceiling.
The trials, and what they used
- Floor 15%: two identical vehicle-controlled phase III trials of 15% gel twice daily in papulopustular rosacea, 329 and 335 patients over 12 weeks, cut inflammatory lesions 58% versus 40% and 51% versus 39% (Thiboutot 2003).
- 20% cream beat its vehicle in 92 acne patients over 3 months (Katsambas 1989), in 116 rosacea patients over 3 months (Bjerke 1999), in 60 acne patients over 45 days with a 61% versus 20% lesion reduction (Iraji 2007) and in facial hyperpigmentation over 24 weeks (Lowe 1998).
- No dose comparison found between 15 and 20%, and nothing tests 10% against vehicle; 5% gel alone cut the acne severity index by 32% where 5% with clindamycin cut it 64%, no placebo arm at that dose (Pazoki-Toroudi 2011).
- 20% is the highest concentration tested and approved, not a measured ceiling.
The pH it needs
A poorly soluble diacid (pKa 4.55 and 5.50); at pH 4.9 more dissolved, partly ionised acid entered mouse skin than at pH 3.9.
pH 5.0 is the point the study measured it working at (mouse skin).
The data have shown that a higher concentration of AZA is retained in the epidermis/dermis layer and the whole skin for the formulation with pH = 4.9 as compared to that with pH = 3.9 at an active loading level of 2.82 mg/cm(2).
Drag the handle along the line. Only what was measured is drawn; between the marks nothing was. Your skin's surface: about 4.7 at rest, 5.1 on a normal day.PMID 18489300PMID 22111946
Who it's for, and who should skip it
Tends to suit
- acne prone
- rosacea
- pigmentation
- oily
- combo
- sensitive
Approach with care
- very sensitive initial
- Clogs poresLow
- Irritation riskModerate
How it fits each skin type
- DryNeutral
- CombinationSuits
- OilySuits
- SensitiveSuits
Often chosen for acne prone, rosacea, pigmentation. Take extra care if any of these apply to you: very sensitive (when first starting).
Where it fits in your routine
Give it eight to twelve weeks, and possibly less: that is simply when it was measured.
What was measured, and in whom
- Measured on: inflammatory lesion count (papules and pustules) in papulopustular rosacea, investigator-counted.
- The evidence is two identical multicentre double-blind vehicle-controlled 12-week trials of 15% gel twice daily, 329 and 335 patients, in which inflammatory lesion counts fell 58% against 40% on vehicle in one study and 51% against 39% in the other.
- Both the papers and the approved labelling report that difference at the end of treatment and tabulate week 12 only; the trials had earlier visits but none is published as the first to separate from vehicle, so 12 weeks is a ceiling and onset may well be earlier.
- A GRADE-assessed systematic review rates the papule and pustule reduction high-certainty, which establishes that the effect is real, not when it appears.
- Pigment is a slower and separate wait - the melasma work uses 20% cream over roughly six months in Fitzpatrick IV-VI skin - and the 2024 US acne guideline rates azelaic acid only a conditional option.
- The 10% sold over the counter has never been trialled this way, so this bucket describes prescription strength; stinging in the first weeks is usual and settles.
Thiboutot D, Thieroff-Ekerdt R, Graupe K, 'Efficacy and safety of azelaic acid (15%) gel as a new treatment for papulopustular rosacea: results from two vehicle-controlled, randomized phase III studies', J Am Acad Dermatol 2003, PMID:12789172 - verified against PubMed. FINACEA (azelaic acid) Gel 15% prescribing information, Clinical Studies, which states the vehicle difference at the end of treatment and reports week 12 only. GRADE-assessed systematic review of rosacea interventions, Br J Dermatol 2019, PMID:30585305 (high-certainty evidence for topical azelaic acid on papules and pustules). Acne clause: PMID:38300170 (AAD 2024 acne guideline, conditional recommendation).
Plays well with
- niacinamide
- humectants
Azelaic Acid, answered
Is Azelaic Acid safe during pregnancy?
Yes. Azelaic Acid is considered safe to use during pregnancy and breastfeeding. As with anything, if you are unsure it is worth a quick word with your doctor or midwife.
Who should avoid Azelaic Acid?
Approach Azelaic Acid with care if any of these apply to you: very sensitive (when first starting). Its irritation risk is moderate, so introduce it slowly and patch test first.
What concentration of Azelaic Acid actually works?
Research tends to show Azelaic Acid starts pulling its weight above 10%. If a brand prints the percentage, that is the number to look for.
Just started Azelaic Acid?
Compare Azelaic Acid with
39 comparisons built, the 5 most looked-up above.
Can you mix Azelaic Acid with
6 pairings built, the 1 most looked-up above.
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Sources & how we reviewed this
- PMID 30585305read in full
- PMID 38300170abstract read, not the full text
- PMID 39440650read in full
- PMID 41011144read in full
- PMID 41923969read in full
What changed on this page
- : redness support score, redness basis, redness source
- : the pH it needs
- : the highest dose tested