Usage: For products ลดริ้วรอย whitening brightens skin It is in the form of a gel, serum, lotion or cream. Mixing method: mix in water (water-phase), which is heat resistant. But should not use the heat for a long time and should be in formulas with a pH in the range of 3-7. Usage rate: 1-8% (4% recommended in combination with Niacinamide 2-4%)