Azelaic acid: the most underrated active for acne and dark spots

If you had to choose a single active for acne, azelaic acid would be the strongest candidate. It is not the most potent for any one thing, but it is the most complete: antibacterial, comedolytic, anti-inflammatory, and depigmenting. All in one molecule. And it is one of the few acne actives safe during pregnancy and breastfeeding.

It is a dicarboxylic acid naturally produced by the yeast Malassezia furfur on human skin. It is also found in grains like wheat, barley, and rye. It is not an exotic ingredient: it is something your skin already knows.

Four mechanisms in one

1. Antibacterial

Azelaic acid inhibits the protein synthesis of Cutibacterium acnes, reducing the bacterial population in the follicle. Unlike topical antibiotics, it does not generate bacterial resistance (same as benzoyl peroxide).

2. Comedolytic

It normalizes follicular keratinization: prevents dead cells from accumulating and forming plugs that clog pores. Fewer plugs = fewer comedones (blackheads and whiteheads).

3. Anti-inflammatory

It inhibits the generation of free radicals by neutrophils and reduces the production of pro-inflammatory cytokines. This explains its efficacy in rosacea (Finacea 15% is a first-line treatment for papulopustular rosacea).

4. Depigmenting

It inhibits tyrosinase, the key enzyme in melanin production. Unlike hydroquinone, azelaic acid only acts on hyperactive melanocytes (those producing too much melanin), not on normal melanocytes. This means it fades dark spots without lightening the surrounding healthy skin.

Fitton & Goa, 1991 (Drugs): Exhaustive pharmacological review documenting the comparable efficacy of 20% azelaic acid to tretinoin, benzoyl peroxide, and topical erythromycin for acne, with a superior tolerability profile.

Clinical evidence

For acne

Thiboutot et al., 2003: Systematic review positioning azelaic acid as a first-line treatment for mild-to-moderate acne. Reductions in inflammatory and non-inflammatory lesions were comparable to topical retinoids and adapalene, with superior tolerability in some studies.

For post-inflammatory hyperpigmentation

Grimes et al., 2011 (Journal of Drugs in Dermatology): Azelaic acid 15% gel in 30 patients with acne + post-inflammatory hyperpigmentation over 16 weeks. Significant reduction in both active lesions and residual dark spots. Especially effective in high-melanin skin (Fitzpatrick IV-VI).

For darker skin tones

Kakita & Lowe, 1998 (Clinical Therapeutics): Azelaic acid 20% cream in patients with facial hyperpigmentation and dark skin. Significant reduction in pigmentary intensity vs vehicle after 24 weeks. Azelaic acid is especially relevant for darker skin because it does not cause hypopigmentation (unlike hydroquinone at high concentrations).

Concentrations and products

Best OTC option

Skincare · Azelaic acid

The Ordinary Azelaic Acid Suspension 10%

10% azelaic acid in suspension. The most accessible over-the-counter option. Multi-function: acne + dark spots + anti-inflammatory. Silicone texture that may pill under makeup.

★★★★★0.0/ 5

12 weeks

Desde

$10

30ml · 2-3 months

Azelaic acid during pregnancy

Azelaic acid is FDA category B: safe during pregnancy and breastfeeding. It is one of three acne actives approved during pregnancy (alongside niacinamide and topical erythromycin).

Retinoids (adapalene, tretinoin, isotretinoin) are contraindicated. Concentrated salicylic acid (BHA) is also avoided. Azelaic acid covers the functions of both: it exfoliates, is antibacterial, and fades gestational melasma.

Acne routine during pregnancy:

1. Gentle cleanser pH 5.5
2. Azelaic acid 10% (morning and night)
3. Niacinamide (safe, sebum control)
4. Moisturizer
5. SPF 50

How to use azelaic acid

Position in the routine

1. Cleansing
2. Azelaic acid ← here (on clean skin)
3. Niacinamide (if using)
4. Moisturizer
5. SPF (morning)

Frequency

• Weeks 1-2: 1x/day (night)
• Week 3+: 2x/day (morning and night)
• Compatible with long-term daily use

Winning combinations

Compatible with everything except

There are no documented incompatibilities. Azelaic acid is the most compatible active on the market.

Azelaic vs other depigmenting agents

Azelaic acid is the safest option for depigmenting during pregnancy and in darker skin (it does not cause hypopigmentation like hydroquinone).

Common mistakes

1. Expecting results in 2 weeks

Azelaic acid needs 8-12 weeks for acne and 12-16 weeks for hyperpigmentation. It is not an emergency treatment.

2. Giving up because of initial stinging

A mild stinging/burning sensation for the first 5-10 minutes after application is normal and disappears with continued use (1-2 weeks). It is not an allergic reaction.

3. Using only for dark spots

Azelaic acid treats active acne simultaneously. Do not wait for the acne to resolve before treating the spots. Do both at the same time.

4. Confusing The Ordinary with prescription-strength

The Ordinary Azelaic Acid 10% is effective for mild acne and dark spots. For moderate acne or rosacea, you need Finacea 15% or Skinoren 20% with a prescription.