Introduction: The Versatile Dicarboxylic Acid

Azelaic acid (AzA) has gained recognition as a multi-functional skincare ingredient. Unlike single-target actives, AzA offers a combination of anti-inflammatory, antibacterial, and keratolytic properties, making it suitable for acne-prone skin, rosacea, and hyperpigmentation.

Originally derived from grains like wheat and barley, AzA has been synthesized for consistent cosmetic use. Today, it is one of the most searched skincare actives, valued for its broad tolerability and clinical support. For cosmetic chemists, it presents opportunities to formulate products that bridge acne care and tone-evening claims.

Mechanism of Action

AzA improves skin health through several key pathways:

• Antimicrobial Activity: Inhibits growth of Cutibacterium acnes, reducing acne lesions.
• Anti-Inflammatory Effects: Decreases reactive oxygen species and inflammatory cytokines, calming redness.
• Keratolytic Action: Normalizes keratinization, preventing follicular blockage and comedones.
• Tyrosinase Inhibition: Reduces melanin production, improving post-inflammatory hyperpigmentation (PIH) and melasma.

Therefore, AzA is effective across acne, rosacea, and hyperpigmentation — a rare multi-claim profile for a single active.

Scientific Evidence

• Clinical studies show 15–20% AzA formulations significantly reduce inflammatory acne lesions after 12 weeks.
• 10% AzA creams have demonstrated improvements in rosacea-related redness and papules.
• AzA has proven efficacy in reducing post-inflammatory dark spots, making it ideal for acne patients with PIH.
• Unlike hydroquinone, AzA is well tolerated long-term and safe for sensitive skin.

INCI & Formulation Considerations

INCI Name: Azelaic Acid

Formulation Guidelines:

• Typical usage: 5–20% depending on format and market positioning
• Solubility: Poorly water-soluble; requires solvents (propylene glycol, PEGs) or encapsulation
• pH range: Works best around 4.0–5.5
• Texture: Higher concentrations can feel gritty; micronized or nano-grade AzA improves sensorials
• Compatibility: Pairs well with niacinamide, tranexamic acid, and retinoids for synergistic tone and acne care

Cosmetic Applications

• Acne-Clearing Creams: Reduce inflammation and bacterial load while calming redness
• Brightening Serums: Target PIH and melasma with 5–10% AzA blends
• Rosacea Relief Gels: Soothing formats that address both redness and bumps
• Dual-Action Formulas: AzA combined with TXA, kojic acid, or niacinamide for multi-pathway hyperpigmentation support

Consumer Benefits

• Reduces acne lesions and prevents clogged pores
• Visibly brightens dark spots and improves uneven tone
• Calms redness and irritation from rosacea or inflammation
• Offers a safe, dermatologist-backed solution without harsh irritation
• Suitable for long-term, daily use

Internal Link Opportunities

• Brightening Actives

Formulation Tips for Chemists

Formulating with AzA requires overcoming solubility and sensorial challenges. To improve usability:

• Use micronized AzA to reduce grittiness.
• Solubilize with propylene glycol or diglycol-based solvents for serums.
• Consider encapsulation systems (liposomes, cyclodextrins) to enhance delivery.
• Buffer pH carefully for stability and tolerability.
• Pair with soothing agents like allantoin, bisabolol, or Centella extracts for sensitive skin claims.

Regulatory Considerations

In the U.S., prescription AzA creams (15–20%) are classified as drugs for acne and rosacea. Cosmetic use is permitted at lower levels, provided claims remain cosmetic in nature. Safe claim examples include:

• “Visibly brightens skin tone”
• “Helps reduce the look of blemishes”
• “Improves the appearance of dark spots”

Avoid drug-style claims such as “treats rosacea” or “cures acne.”

Future Outlook

Azelaic acid is uniquely positioned at the intersection of acne care and brightening skincare. As consumer awareness grows, demand will increase for cosmetic-grade AzA formats that are smoother, more elegant, and combined with other brightening actives. For chemists, the opportunity lies in using advanced delivery systems to maximize AzA’s efficacy while ensuring tolerability. This positions AzA as a long-term, dermatologist-friendly active that resonates with both professionals and consumers.