★Is Kojic Acid Powder water-soluble or oil-soluble?
Kojic Acid is water-soluble, with good solubility in water phase, suitable for aqueous and emulsified formulas.
★What products is Kojic Acid Powder suitable for?
Whitening serum, spot-correcting cream, brightening toner, mask, body whitening lotion, post-acne mark repair products.
★What is the recommended usage rate?
Recommended addition concentration: 0.5%–2%, adjusted according to product positioning and mildness requirement.
★What pH range is suitable for Kojic Acid Powder?
It is stable and effective in pH 4.0–6.0 (weakly acidic environment), alkaline environment will accelerate its degradation.
★What ingredients can be compounded with Kojic Acid Powder?
It can be used with arbutin, niacinamide, tranexamic acid, VC derivatives, hyaluronic acid to enhance whitening effect.
★How does Kojic Acid compare to Kojic Dipalmitate?
Kojic Acid: Higher whitening efficacy, but unstable – easily oxidized (turns yellow/brown), can cause skin irritation at higher concentrations, and is water-soluble.
★Does Kojic Acid cause skin irritation or sensitivity?
At concentrations above 2%, some individuals may experience mild redness, stinging, or contact dermatitis. It is recommended to start at 0.5-1% for sensitive skin formulations. We strongly advise patch testing before widespread use. Our kojic acid passes standard skin irritation tests, but individual sensitivity varies.
★Is Kojic Acid safe to use in leave-on products?
Yes, when used within recommended concentrations (≤2% for leave-on). However, due to its potential for irritation and instability, many formulators prefer using kojic acid in rinse-off products (masks, cleansers) or combining it with stabilizing agents. For leave-on serums, we recommend using it with antioxidants and chelators, and advising customers to avoid sun exposure without SPF.
★Is Kojic Acid approved for cosmetic use in the EU, USA, and China?
EU: Allowed. Listed in CosIng with no concentration restriction, but SCCS has issued opinions that up to 1% in leave-on products is safe. Many EU brands use 0.5-2%.
USA: Allowed as a cosmetic ingredient. FDA has no specific ban.
China (NMPA): Listed in IECIC 2021 (INCI: 曲酸) with a maximum concentration of 2% for leave-on products. We provide full registration documents including COA, MSDS, TDS, and China compliance declaration.
