I need the vitamin C serum to use with my derma roller so when I saw the random box I bought it right away. The box came with so many goodies but I haven't used anything yet besides the vitamin C serum. It does feel a bit sticky at first but as your skin absorbs the product, the stickiness does go away. The only inconvenience of this product is that it must be refrigerated after opening. Other than that, it's perfect.