C SCRIPTION? brightening serum. This dermatologist tested serum is powered by 25% brightening ingredients, including 20% THD ascorbate–a highly potent oil-soluble form of Vitamin C and a 4% hexylresorcinol complex, that synergistically brighten discoloration while minimizing the appearance of fine lines and supporting collagen for firmer-looking skin. You’ll see clinical results with visibly brighter skin, dark spots fading away and a glowing, even complexion. Brighten up, dullness is behind you.