Common Name(s): Nonanedioic acid,lepargylic acid
CAS Number: 123-99-9
DESCRIPTION
What It Does: Reduces acne, evens skin tone, calms rosacea, and reduces hyperpigmentation through multiple complementary mechanisms.
Why It's Used: Multi-action gold standard for hyperpigmentation, acne, rosacea, and post-inflammatory hyperpigmentation (pih) โ well-tolerated by all skin tones.
How It Works: Inhibits tyrosinase (melanin synthesis) and abnormal melanocyte proliferation. inhibits 5-alpha-reductase (sebum control). antimicrobial against p. acnes and malassezia. anti-inflammatory via nf-kb pathway inhibition.
Typically Found In: Brightening serums,anti-acne treatments,rosacea products,hyperpigmentation formulations
TECHNICAL DETAILS
Primary Category: Active ingredient โ dicarboxylic acid
Secondary Functions: Anti-acne,rosacea management,sebum control
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 5%โ20% (otc 5โ10%; prescription 15โ20%)
SOURCING & ETHICS
Vegan Status: Conditional - supplier confirmation required
Halal Status: Unverified - supplier confirmation required
Source Notes: Naturally from malassezia yeast on skin; produced by ozonolysis of oleic acid commercially. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 2/5 โ low to moderate; initial tingling expected
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: Initial tingling and stinging normalizes within 2โ4 weeks of regular use.
Safe for Sensitive Skin: Use with caution โ transient tingling common during introduction
SAFETY & COMPATIBILITY
Safety Profile: Excellent long-term safety. fda-approved for acne (benzaclin) and rosacea (finacea). ewg score: 1.
Works Well With: Ceramides,niacinamide,hyaluronic acid,spf
Avoid Combining With: Multiple exfoliating acids simultaneously; high concentrations without spf
SCIENTIFIC NOTE
Azelaic acid's combined tyrosinase inhibition + abnormal melanocyte selectivity (normalizes only overactive melanocytes, unlike hydroquinone) makes it uniquely safe for long-term use without bleaching normal-pigmented skin.
Last Verified: 2026-03-12
Primary Sources: Cosing database,draelos azelaic acid review,fda drug approval database