A practical comparison of two of the most sought-after whitening actives — efficacy, stability, formulation tips, and regulatory considerations.
When formulating skin-brightening products, arbutin and kojic acid are two of the most widely used actives. Both inhibit melanin production, but they differ significantly in stability, pH tolerance, and formulation compatibility. Here's a practical breakdown to help you choose.
Arbutin (both alpha and beta forms) works by inhibiting tyrosinase activity, the enzyme responsible for melanin synthesis. Alpha-arbutin is considered the more potent and stable of the two, offering up to 10x greater tyrosinase inhibition than beta-arbutin at equivalent concentrations.
Kojic acid also inhibits tyrosinase but through a chelation mechanism — it binds to copper at the enzyme's active site. This makes it effective but more prone to oxidation, especially in aqueous formulations.
- Arbutin: Stable across a wide pH range (5.0–7.0), compatible with most emulsion systems, and less prone to color change. Alpha-arbutin is particularly stable and water-soluble.
- Kojic Acid: Best formulated at pH 4.0–5.5. Sensitive to light, heat, and oxidation — requires chelating agents (EDTA), antioxidants, and opaque packaging. Prone to browning over time.
| Active |
Typical Range |
Notes |
| Alpha-Arbutin |
0.2%–2% |
Most effective at 1%–2% |
| Beta-Arbutin |
2%–5% |
Lower potency, higher concentration needed |
| Kojic Acid |
0.5%–2% |
Often combined with vitamin C or glycolic acid |
Both ingredients are widely accepted in global markets, with some nuances:
- EU: Both permitted in cosmetics. Kojic acid is under ongoing safety review by the SCCS.
- Japan: Both are commonly used; kojic acid has a longer history in J-beauty.
- China: Both included in the IECIC inventory. Arbutin (alpha and beta) is specifically listed.
For serums and leave-on products targeting even skin tone, alpha-arbutin offers better stability and easier formulation. For rinse-off products or when combined with exfoliating acids, kojic acid dipalmitate (a more stable ester derivative) is worth considering.
At YUXI Technology, we supply both alpha-arbutin (99% min purity) and kojic acid dipalmitate in bulk quantities with full COA documentation. Contact us for samples or pricing.
