Decoded Korea

Vitamin C serums are sold at 10%, 15%, 20%, and sometimes 30% concentration. These are high numbers for an active ingredient. For comparison, the EU recently capped retinol at 0.3% in most cosmetics. So how is 20% vitamin C legal when 0.3% retinol is the EU limit? Because no country regulates L-Ascorbic Acid concentration in cosmetics. None of the 10 markets in our database — EU, Korea, Japan, China, Taiwan, ASEAN, Brazil, Argentina, the US, or Canada — has a limit. 76 forms of vitamin C Our database contains 76 ingredients with "Ascorbic" or "Ascorbyl" in their INCI names. Vitamin C in skincare is not a single ingredient — it is a family of compounds, each with different stability, potency, and skin penetration characteristics. The ones consumers encounter most often: Form INCI name Characteristics L-Ascorbic Acid Ascorbic Acid Most potent, least stable. Requires low pH. The form used in 10–20% serums MAP Magnesium Ascorbyl Phosphate Stable,...