Quick Comparison
| Allantoin | Azelaic Acid | |
|---|---|---|
| Typical Concentration | Concentrations: 0.5-2% in most formulations. Often combined with other soothing ingredients. Apply as part of regular skincare routine. Safe for all ages and skin types, including infants. | 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 (cream, lotion, serum, ointment). Compatible with all other skincare ingredients. | Topical (gel, cream, serum). Slightly gritty texture in some formulations. Apply to clean skin. |
| Research Papers | 8 papers | 9 papers |
| Categories |
Mechanism of Action
Allantoin
Allantoin (5-ureidohydantoin) stimulates cell proliferation and tissue regeneration by promoting fibroblast activity, keratinocyte proliferation, and extracellular matrix synthesis including collagen and glycosaminoglycans. It acts as a mild keratolytic by promoting the natural desquamation process—loosening corneocyte adhesion and facilitating shedding—without the irritation, pH disruption, or barrier compromise associated with alpha- or beta-hydroxy acids. Allantoin has anti-inflammatory properties through modulation of prostaglandin synthesis (inhibiting COX-2 and reducing PGE2) and may downregulate pro-inflammatory cytokines. Its moisturizing effect comes from increasing the water-binding capacity of the extracellular matrix and stratum corneum; it is highly soluble and forms hydrogen bonds with water. Allantoin also promotes wound epithelialization. Its safety profile—non-irritating, non-sensitizing, non-comedogenic—makes it suitable for compromised skin, post-procedure care, and infant formulations.
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
Allantoin
Common
None. Allantoin is non-irritating, non-sensitizing, and non-comedogenic.
Serious
None.
Rare
Allergic reaction is extremely rare.
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
Allantoin →
A gentle compound found naturally in comfrey root, chamomile, and wheat sprouts that promotes skin healing, moisturization, and the shedding of dead skin cells. Allantoin has been used in dermatology for over 70 years and is one of the most universally tolerated ingredients — it soothes, protects, and promotes recovery without any known irritation potential. Found in everything from diaper cream to post-procedure products.
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).