Quick Comparison
| Licorice Root Extract | Niacinamide | |
|---|---|---|
| Typical Concentration | Concentrations vary; glabridin at 0.1-0.4% is the most active brightening component. Full extract at 1-4%. Apply morning and/or night. Safe for all skin types. Often combined with niacinamide and arbutin for enhanced brightening. | Concentrations: 2-10%. 5% is the most studied concentration and provides the best balance of efficacy and tolerability. Higher concentrations (10%) are available but may cause irritation in sensitive skin without proportional benefit. Apply morning and/or night. |
| Application | Topical (serum, cream, toner). Very stable in formulation. Compatible with most active ingredients. | Topical (serum, moisturizer, toner). Water-soluble. Stable in formulation. Compatible with most actives. |
| Research Papers | 10 papers | 10 papers |
| Categories |
Mechanism of Action
Licorice Root Extract
Glabridin competitively inhibits tyrosinase by binding copper active site (CuA, CuB), blocking tyrosine to L-DOPA hydroxylation and DOPA to dopaquinone oxidation. Also inhibits tyrosinase-related protein 1 (TRP-1). Liquiritin disperses existing melanin via melanosome transfer inhibition and autophagy pathway upregulation in keratinocytes. Glycyrrhizin inhibits COX-2 and 5-lipoxygenase, reducing prostaglandin and leukotriene production. Multi-mechanism brightening: tyrosinase inhibition, melanin dispersal, anti-inflammation. Unlike hydroquinone, no melanocyte cytotoxicity — suitable for long-term use and all skin tones. Glabridin has free radical scavenging antioxidant activity. Glycyrrhizin's 11-beta-HSD inhibition has minimal systemic effect with topical use.
Niacinamide
Niacinamide is converted to NAD+ via the Preiss-Handler pathway—essential for cellular respiration, DNA repair (PARP), and sirtuin regulation. In keratinocytes, it upregulates serine palmitoyltransferase and fatty acid elongases, increasing ceramide synthesis and strengthening the barrier. It inhibits melanosome transfer by downregulating protease-activated receptor-2 (PAR-2) on keratinocytes—brightening without tyrosinase inhibition. In sebocytes, it normalizes lipid synthesis and reduces sebum (possibly via AMPK). Niacinamide inhibits NF-kB translocation, suppressing IL-1beta, TNF-alpha, and IL-8. It inhibits phosphodiesterase, increasing cAMP and modulating keratinocyte differentiation. These multi-pathway effects explain broad efficacy across barrier repair, brightening, acne, and anti-aging.
Risks & Safety
Licorice Root Extract
Common
Very well-tolerated.
Serious
None documented topically. Oral licorice (glycyrrhizin) can elevate blood pressure, but topical use does not have this effect.
Rare
Allergic contact dermatitis.
Niacinamide
Common
Very well-tolerated at 2-5%. Flushing/redness at concentrations above 5% in some individuals.
Serious
None documented.
Rare
Contact dermatitis (uncommon). Old advice to avoid combining with vitamin C is largely debunked at product pH levels.
Full Profiles
Licorice Root Extract →
A natural brightening and anti-inflammatory ingredient derived from Glycyrrhiza glabra root. The key actives — glabridin, liquiritin, and glycyrrhizin — inhibit melanin production, reduce inflammation, and soothe irritation. Licorice root is one of the most effective and gentle brightening ingredients available, with lower irritation risk than vitamin C or hydroquinone.
Niacinamide →
A true multitasker — niacinamide (vitamin B3) addresses almost every skin concern simultaneously. It strengthens the skin barrier by boosting ceramide production, reduces hyperpigmentation by inhibiting melanosome transfer, controls sebum production, minimizes pore appearance, reduces redness, and has anti-aging benefits. One of the most versatile and well-tolerated actives in skincare.