Azelaic Acid
Also known as: Nonanedioic Acid, Azelaic Acid 15%, Azelaic Acid 20%
Key Takeaways
- Azelaic acid is anti-inflammatory, antibacterial, and brightening — making it one of the most versatile actives in skincare
- It is one of the only acids clinically approved for rosacea-prone and sensitive skin
- Effective for post-inflammatory hyperpigmentation, melasma, and acne at concentrations of 10-20%
- Does not cause photosensitivity and can be safely used in AM and PM routines
A naturally occurring dicarboxylic acid with anti-inflammatory, antibacterial, and brightening properties. One of the few actives safe for rosacea-prone and sensitive skin, and among the most well-researched ingredients for melasma and post-inflammatory hyperpigmentation.
Skin Type Compatibility
Skin Tone Notes
Particularly beneficial for deeper skin tones prone to post-inflammatory hyperpigmentation. Safe across the entire Fitzpatrick scale with no photosensitivity concerns.
What It Does
Azelaic acid works through three primary mechanisms. It inhibits tyrosinase, the enzyme responsible for melanin production, reducing hyperpigmentation and evening skin tone. It has direct antibacterial action against Cutibacterium acnes and Staphylococcus epidermidis, making it effective against bacterial acne. Its anti-inflammatory properties reduce the redness and vascular reactivity associated with rosacea, distinguishing it from most other acids that can aggravate the condition.
Concerns Addressed
How To Use
Apply to clean, dry skin before moisturizer. Can be used AM and/or PM. At 10% (OTC), daily use is appropriate from the start. Prescription concentrations (15-20%) may warrant a slower introduction. No mandatory wait time between application and other products. Consistent daily use yields the best results for pigmentation and rosacea — visible improvement typically takes 4-8 weeks.
Pairs Well With
Niacinamide
A form of vitamin B3 that strengthens the skin barrier, reduces inflammation, and regulates sebum production. One of the most versatile and well-studied active ingredients in modern skincare.
Hyaluronic Acid
A naturally occurring polysaccharide that can hold up to 1000 times its weight in water. Hyaluronic acid is one of the most effective and universally tolerated hydrating ingredients in skincare, working for every skin type and pairing seamlessly with virtually all actives.
Side Effects
Mild tingling or warmth upon application is common when starting out, especially at higher concentrations. This typically subsides within the first few weeks. Rarely causes significant irritation. No photosensitivity — can be used in AM without added sun sensitivity concerns, though SPF is always recommended.
Key Studies
Azelaic acid 15% gel significantly reduced inflammatory lesion counts and erythema compared to placebo, with a favorable tolerability profile in rosacea patients.
Azelaic acid 20% was comparably effective to hydroquinone 4% for melasma treatment with fewer side effects, including no risk of ochronosis.
What Is Azelaic Acid?
Azelaic acid is a naturally occurring dicarboxylic acid found in grains like wheat, barley, and rye. It is produced in small amounts by skin-resident yeast (Malassezia furfur) and is also synthesized for use in skincare formulations. Unlike most acids used in skincare, azelaic acid’s primary mechanisms are not exfoliation — it works through direct antibacterial, anti-inflammatory, and tyrosinase-inhibiting pathways.
How Does Azelaic Acid Work?
Azelaic acid inhibits tyrosinase, the key enzyme in melanin synthesis, selectively targeting abnormally active melanocytes without affecting normal pigmentation. This makes it effective for hyperpigmentation without the risk of rebound or the bleaching of surrounding healthy skin. Its antibacterial action disrupts bacterial protein synthesis in acne-causing bacteria, and its anti-inflammatory effects reduce the cytokine activity that drives rosacea flares and post-inflammatory redness. It also has mild comedolytic properties that contribute to smoother skin texture over time.
Who Should Use Azelaic Acid?
Azelaic acid is suitable for all skin types, but it is particularly valuable for people who cannot tolerate stronger actives. It is one of the best options for sensitive and rosacea-prone skin. People dealing with post-inflammatory hyperpigmentation, melasma, hormonal breakouts, or persistent redness will see the most benefit. It is also considered safe during pregnancy at 10-15% (consult a physician), making it one of few effective actives available to pregnant individuals dealing with acne or pigmentation.
Frequently Asked Questions
Is azelaic acid safe for rosacea?
Yes. Azelaic acid is one of the few topical actives with clinical evidence specifically for rosacea treatment. It reduces redness, inflammatory papules, and pustules. Prescription-strength 15% gel (Finacea) is FDA-approved for rosacea. It does not cause the flushing or irritation that many other acids do.
What is the difference between OTC and prescription azelaic acid?
OTC formulations are typically 10%, while prescription versions reach 15-20%. Studies show that 10% is effective for hyperpigmentation and acne. For rosacea, the 15% prescription gel has the strongest clinical evidence. The 20% cream is primarily studied for melasma.
Does azelaic acid make skin photosensitive?
No. Unlike AHAs and retinoids, azelaic acid does not increase photosensitivity. It can be used in the morning without the same sun-exposure concerns. Daily SPF is still recommended as a general practice but is not uniquely required because of azelaic acid.