Quick Comparison
| Aloe Vera | Azelaic Acid | |
|---|---|---|
| Typical Concentration | Apply pure aloe vera gel or products containing high concentrations (>50% aloe). For sunburn: apply liberally and frequently. For daily use as a soothing moisturizer: apply after cleansing. Refrigerating aloe gel provides additional cooling relief. | OTC: 10% (The Ordinary). Prescription: 15% gel (Finacea for rosacea), 20% cream (Azelex for acne). Apply twice daily. Well-tolerated but may sting/itch initially. Full effects at 8-12 weeks. |
| Application | Topical (gel, cream, lotion). Pure inner leaf gel or standardized extracts. Apply to clean skin. | Topical (gel, cream, serum). Slightly gritty texture in some formulations. Apply to clean skin. |
| Research Papers | 10 papers | 9 papers |
| Categories |
Mechanism of Action
Aloe Vera
Acemannan (acetylated mannan polysaccharide) is the primary bioactive—it binds to macrophage mannose receptors and stimulates macrophage phagocytosis, cytokine release (IL-1, TNF-α), and fibroblast proliferation via growth factor induction, accelerating wound healing and granulation tissue formation. Acemannan also promotes keratinocyte proliferation and migration. Aloesin (a chromone) inhibits tyrosinase and tyrosinase-related protein-1 (TRP-1), providing mild brightening. Aloe-emodin has antibacterial activity against Gram-positive bacteria and antiviral effects. Salicylic acid naturally present in aloe inhibits cyclooxygenase (COX), providing mild anti-inflammatory and analgesic effects. The gel matrix forms a semi-occlusive film that reduces transepidermal water loss (TEWL). Aloe contains glucomannan, which acts as a humectant. Proteolytic enzymes (bradykinase) may contribute to anti-inflammatory activity. Use inner leaf gel to avoid anthraquinones in the latex that can cause irritation.
Azelaic Acid
Azelaic acid exhibits multi-modal activity: (1) Tyrosinase inhibition—competitively inhibits tyrosinase selectively in hyperactive melanocytes (melasma, PIH) while sparing normal ones; may involve mitochondrial enzyme interference in dysregulated melanocytes. (2) Antimicrobial—bacteriostatic against Cutibacterium acnes by inhibiting bacterial protein synthesis. (3) Comedolytic—normalizes follicular keratinization, reducing hyperkeratinization and corneocyte cohesion; may modulate keratinocyte differentiation. (4) Anti-inflammatory—scavenges ROS, inhibits neutrophil free radicals, reduces pro-inflammatory cytokines. Inhibits 5-alpha-reductase in sebocytes, potentially reducing sebum. Multi-pathway activity explains efficacy in acne, rosacea, and hyperpigmentation. Safe during pregnancy.
Risks & Safety
Aloe Vera
Common
May cause drying if used alone (aloe lacks occlusive properties, so moisture can evaporate).
Serious
None from topical use.
Rare
Allergic contact dermatitis (especially to compounds in the latex/outer leaf, not the inner gel). Oral aloe vera is a separate concern with laxative effects.
Azelaic Acid
Common
Stinging, burning, itching on initial application (usually subsides within 2 weeks). Mild dryness.
Serious
None. Safe during pregnancy and breastfeeding.
Rare
Allergic contact dermatitis, hypopigmentation (rare at cosmetic concentrations).
Full Profiles
Aloe Vera →
One of the oldest and most recognized soothing ingredients, used for millennia for burns, wounds, and skin irritation. Aloe vera gel contains over 75 active compounds including polysaccharides, vitamins, minerals, and enzymes. It provides immediate cooling, hydration, and anti-inflammatory relief. The evidence is strongest for wound healing, sunburn recovery, and moisturization.
Azelaic Acid →
A dicarboxylic acid naturally produced by yeast on the skin. Azelaic acid is a true multi-tasker that treats acne, rosacea, and hyperpigmentation simultaneously. It is one of the few active ingredients considered safe during pregnancy, and it uniquely targets only abnormal melanocytes — meaning it brightens dark spots without lightening normal skin. Effective for both inflammatory acne and post-inflammatory hyperpigmentation (PIH).