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 we’ve 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