Kate Somerville Kx Active Concentrates Vitamin B3+Vitamin C Serum 1oz/ 30ML/ FULL SIZE. Retails for $98 at fine stores. This lightweight clinical serum visibly improves tone, texture and clarity as it brightens skin. Vitamins B + C work together to target discoloration and unevenness, improving radiance and luminosity. Condition is "New". Shipped with USPS First Class.