Azelaic Acid
Azelaic Acid — evidence, uses & status

Class: small_molecule
Synonyms: AzA
azaleic acid (common misspelling)
nonanedioic acid
1,7-heptanedicarboxylic acid
INCI: Azelaic Acid
Function tags: skin appearance (cosmetic)
hyperpigmentation appearance
even tone / brightening
blemish appearance
redness appearance
Overall evidence grade: B
WADA prohibited: no
Last updated: 2026-07-20

In brief: Azelaic acid (AzA) is a dicarboxylic acid from grains and skin yeast, and one of dermatology's most versatile, best-tolerated actives — calming the look of redness, clearing the appearance of breakouts, and fading pigment through selective tyrosinase inhibition. A 2023 systematic review of 43 randomised trials found it more effective than vehicle for acne, rosacea, and melasma, with 20% azelaic comparable to 4% hydroquinone for melasma. It is graded B rather than A on honest discipline: the strongest data sits at prescription strength (15–20%), the cosmetic-accessible form is milder, results are formulation-dependent (poor solubility and penetration), and no RCTs support an anti-aging use. The prescription forms are medicines for acne and rosacea and a dermatologist's call.

## Identity

a **dicarboxylic acid** (nonanedioic acid, a nine-carbon chain) found naturally in barley, wheat, and rye, and produced on skin by the commensal yeast *Malassezia*. In skincare it is a small, well-tolerated multi-use active — a single molecule with anti-pigment (tyrosinase-inhibiting), calming, and pore-clearing action. It exists as a lower-strength **cosmetic** ingredient (often around 10%, or as gentler azelaic derivatives) and as higher-strength **prescription** medicines (15% gel, 20% cream) for acne and rosacea. For the full readable explanation of what it is and how it works, see the companion guide, [what is azelaic acid?](/learn/what-is-azelaic-acid)

## Development & history

- A naturally occurring dicarboxylic acid, studied in dermatology for decades.
- Established as a prescription topical for acne (20% cream) and rosacea (15% gel), with a large randomised-trial base built up across the 1980s–2010s.
- Adopted into cosmetic skincare at lower strengths and as derivatives (such as potassium azeloyl diglycinate) for the appearance of uneven tone, blemishes, and redness.
- Consolidated by a 2023 systematic review (King et al.) pooling 43 randomised controlled trials across acne, rosacea, and melasma.

## Mechanism (as proposed)

a dicarboxylic acid with several documented actions in skin: it **inhibits tyrosinase** (the rate-limiting enzyme of melanin synthesis) preferentially in *overactive* melanocytes, so it tends to fade a dark spot without lightening the normal skin around it; it scavenges reactive oxygen species (the basis of its calming, redness-reducing use); and it is mildly antimicrobial and normalises follicular keratinisation (relevant to the appearance of breakouts). Its poor water solubility and limited skin penetration make the delivery vehicle central — which is why results are formulation-dependent rather than guaranteed by "contains azelaic."

## Related reading

- The full readable guide: [what is azelaic acid?](/learn/what-is-azelaic-acid)
- Where azelaic ranks among the pigment actives, in [best ingredients for dark spots and hyperpigmentation](/learn/best-ingredients-for-hyperpigmentation).
- Head-to-heads: [azelaic vs niacinamide](/learn/azelaic-vs-niacinamide) and [azelaic acid vs vitamin C](/learn/azelaic-acid-vs-vitamin-c).
- The other brighteners it pairs with: [niacinamide](/compound/niacinamide), [vitamin C](/compound/vitamin-c), [alpha arbutin](/compound/alpha-arbutin), and [kojic acid](/compound/kojic-acid).
- The non-negotiable base for any pigment work: [how to use sunscreen](/learn/how-to-use-sunscreen).

Evidence grades by outcome:
outcome: Acne (appearance, cosmetic-strength topical)
grade: B
base: King 2023 systematic review (43 RCTs) — azelaic more effective than vehicle; comparable to topical retinoids on inflammatory lesions in review-level evidence
effect: Reduced appearance of breakouts and post-acne marks
caveat: Strongest data at prescription 15–20%; cosmetic-accessible form is milder; acne is a medical condition
outcome: Rosacea — redness & bumps (appearance)
grade: B
base: King 2023 — 15% gel comparable to (or better than) metronidazole in review-level evidence
effect: Calmer-looking redness, papules, and pustules
caveat: The prescription 15% gel holds the strongest data; rosacea is a condition for a dermatologist
outcome: Hyperpigmentation / PIH (appearance)
grade: B
base: King 2023; selective tyrosinase inhibition of overactive melanocytes, fading a spot without lightening surrounding skin
effect: Gradual fading of dark spots and post-inflammatory marks
caveat: Gradual; formulation-dependent; daily sun protection essential
outcome: Melasma (appearance)
grade: B
base: King 2023 + Albzea 2023 meta-analysis — 20% azelaic comparable to 4% hydroquinone and better than 2% hydroquinone; lower melasma severity index than hydroquinone across pooled trials
effect: Visible evening of melasma-related pigmentation over weeks to months
caveat: Strongest at 20% (prescription); melasma recurs and needs a dermatologist for stubborn cases
outcome: Skin-aging / wrinkles
grade: F
base: King 2023 found no eligible RCTs for skin-aging
effect: Not demonstrated
caveat: No controlled evidence supports an anti-wrinkle claim
outcome: "Azelaic acid derivative" equivalence
grade: F
base: Marketing claim
caveat: No human study has compared a derivative head-to-head against azelaic acid itself, so the equivalence has never been tested. The 43 pooled RCTs and the melasma meta-analysis enrolled azelaic acid at 15–20% with no derivative arm; the one lower-strength comparison varied the vehicle, not the molecule. Relabelling to a derivative is an honest ingredient name — inheriting the azelaic trial record is not.
outcome: Safety & tolerability (topical)
base: Broad cosmetic and prescription use; well tolerated
effect: Generally well tolerated; widely regarded as often compatible with pregnancy
caveat: Mild, transient tingling is common early; patch test. Pregnancy compatibility is a doctor's call to confirm, not medical clearance

Legal status:
region: INT
status: Lawful cosmetic (lower-strength / derivative); prescription at 15–20%
note: Topical azelaic acid is a lawful cosmetic ingredient at cosmetic strengths (products are often around 10%, or use gentler azelaic derivatives). Separately, 15% gel and 20% cream are regulated PRESCRIPTION medicines for acne and rosacea in many regions — stronger forms that are a dermatologist's decision and outside the scope of this cosmetic grade.

Cosmetic claims:
allowed: for the appearance of a clearer, more even complexion
helps reduce the look of dark spots and blemishes
for calmer, less red-looking skin
supports a smoother-looking, more uniform tone
forbidden: treats acne
treats rosacea
treats melasma
cures dark spots
inhibits tyrosinase
anti-inflammatory
antibacterial
reverses aging
anti-wrinkle

Honest note: This entry grades the COSMETIC-accessible topical form, framed around the appearance of skin. Prescription 15% gel and 20% cream are regulated medicines for acne and rosacea — stronger, and a dermatologist's decision, not something to self-manage. There is no good evidence azelaic acid does anything for wrinkles. Persistent acne, rosacea, or melasma is best assessed by a dermatologist; melasma in particular recurs and needs strict daily sun protection. Azelaic acid is widely regarded as often compatible with pregnancy, but that is a conversation to confirm with your own doctor, not medical clearance.

Sources:
King S, Campbell J, Rowe R, Daly ML, Moncrieff G, Maybury C. A systematic review to evaluate the efficacy of azelaic acid in the management of acne, rosacea, melasma and skin aging. J Cosmet Dermatol. 2023;22(10):2650-2662.
Albzea W, AlRashidi R, Alkandari D, et al. Azelaic Acid Versus Hydroquinone for Managing Patients With Melasma: Systematic Review and Meta-Analysis of Randomized Controlled Trials. Cureus. 2023;15(7):e41796.
McKesey J, Tovar-Garza A, Pandya AG. Melasma Treatment: An Evidence-Based Review. Am J Clin Dermatol. 2020;21(2):173-225.