Brightening / Pigmentation

Azelaic Acid

INCI: Azelaic Acid · CAS 123-99-9

Azelaic acid is a naturally occurring dicarboxylic acid used in skincare to help even tone, calm blemish-prone skin and reduce the look of redness.

INCIAzelaic Acid
CAS123-99-9
Use levelcosmetic up to ~10%
Solubilitypoorly water-soluble (formulation challenge)
pH / stability~4–5
RegulatoryListed in EU CosIng; higher strengths are prescription-only

What it does

  • Helps even skin tone and fade the look of post-blemish marks.
  • Supports clearer, blemish-prone skin.
  • Helps reduce the appearance of redness.

How it works

Azelaic acid is widely documented to have several complementary actions: it moderates melanin production in overactive melanocytes (helping uneven tone), has antibacterial and keratolytic effects useful for blemish-prone skin, and calms visible redness. Its main formulation challenge is low solubility, so it is often used as a suspension or as a more soluble derivative such as potassium azeloyl diglycinate.

Use level

Typical use level
cosmetic up to ~10%

Cosmetic products commonly use up to about 10%. Prescription formulations at 15–20% are medicines and outside cosmetic scope. Derivatives are used at lower equivalent levels.

Formulation considerations

  • Poorly soluble in water and oil; often suspended or used as a derivative.
  • Works in mildly acidic products.
  • Texture and grittiness are common challenges with the free acid.

What it pairs with & what to avoid

Pairs well with

  • Niacinamide
  • Salicylic acid (blemish-prone skin)
  • Gentle hydrators to offset dryness

Use with care / avoid

  • Layering many strong acids at once (irritation risk)

Regulatory status

Azelaic acid is listed in the EU CosIng database for cosmetic use. Higher-strength products (15–20%) are regulated as medicines in many markets.

Common questions

What percentage of azelaic acid is in skincare?

Cosmetic products commonly use up to about 10%. The 15–20% strengths are prescription medicines.

Is azelaic acid good for redness and blemishes?

It is widely documented to help with the look of redness and to support blemish-prone skin, alongside evening tone.

Can I use azelaic acid with niacinamide?

Yes, they are commonly paired and generally well tolerated together.

Related monographs

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