Quick Comparison
| Azelaic Acid | Tranexamic Acid | |
|---|---|---|
| Typical Concentration | 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. | Topical: 2-5% in serum or cream, applied twice daily. Oral (off-label for melasma): 250 mg twice daily — requires medical supervision. Can be combined with other brightening agents. Results visible at 8-12 weeks. Especially effective for melasma. |
| Application | Topical (gel, cream, serum). Slightly gritty texture in some formulations. Apply to clean skin. | Topical (serum, cream) or oral (tablets, off-label). Topical preferred for safety. Oral is more effective but carries systemic risks. |
| Research Papers | 9 papers | 10 papers |
| Categories |
Mechanism of Action
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.
Tranexamic Acid
Tranexamic acid (TXA) is a lysine analogue that competitively inhibits plasminogen activation—binding lysine-binding sites and preventing conversion to plasmin by tPA and uPA. Plasmin normally activates multiple pathways: converts latent TGF-beta to active form, stimulates keratinocyte release of arachidonic acid and prostaglandins (PGE2, PGF2-alpha), and increases SCF and bFGF—all stimulating melanocyte proliferation and melanogenesis. By blocking plasmin, TXA interrupts this paracrine cascade, reducing melanin through a mechanism independent of tyrosinase. TXA also inhibits VEGF and reduces angiogenesis—addressing melasma's vascular component. May reduce UV-induced plasmin in keratinocytes. This unique mechanism makes TXA synergistic with tyrosinase inhibitors for stubborn melasma.
Risks & Safety
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).
Tranexamic Acid
Rare
Topical form has minimal systemic absorption and low risk.
Full Profiles
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).
Tranexamic Acid →
Originally an oral medication for heavy menstrual bleeding, tranexamic acid (TXA) has emerged as one of the most effective treatments for melasma and stubborn hyperpigmentation that does not respond to conventional treatments. It works through a unique mechanism — blocking plasmin-mediated stimulation of melanocytes — that is different from tyrosinase inhibitors, making it an excellent combination partner.