Why do I need Plum's Vitamin C Face Serum? Vitamin C (above 10% concentration) when applied on skin is proven to act on hyperpigmentation dark spots oxidative damage like wrinkles and provide a boost to the natural glow of your skin. This face serum is thoughtfully formulated for targeted efficacy safety and all-round results. It contains Ethyl Ascorbic Acid (EAA 15% active) a water-soluble form of Vitamin C that penetrates skin quickly and stays stable for longer without oxidizing. When we say 15% we mean 15% - because weve added 17.5% of EAA which contains 86% active Vitamin C by weight. In our consumer study we found - 83% users saw enhanced skin glow & 32% reduction in dark spots. This super-effective Vitamin C face serum is all skin type friendly and can be used in the day or night. *Self assessment study conducted on 41 subjects with varying skin types