Vitamin C is a powerful antioxidant that also helps to fade dark spots and even the skin tone. Available in a vast selection of cosmetics, it's the ideal ingredient if you're looking for a radiance booster for dull and tired skin. You can also combine it with glycolic acid in order to improve the results. If you're feeling that your skin is lacking vitality and radiance, feeling a bit dull, then Vitamin C is truly the answer you're looking for.