If you have brown face spots, this product is one of the main ones you should be looking at, as it works on optimal lightening and dark spots prevention. Apply the serum (has a bit of a gel feel to it) over night after you've perfectly cleansed your face. Vitamin C, which is gradually released for long-lasting action, reduces the number of melanin pigments in the epidermis. The intense peeling action of glycolic acid activates the elimination of cells loaded with pigments.