Obagi Clarifying Serum Fx is a clinically proven formulation to lighten and brighten the skin. The key ingredients in Obagi Clarifying Serum Fx are Arbutin (7%) and 10% L-ascorbic Acid (Vitamin C). Arubutin is a key ingredient in skin-brightening. Arbutin works by improving the appearance of hyperpigmentation for a more even complexion. L-ascorbic Acid is a potent for of Vitamin C. L-ascorbic Acid has antioxidant properties that minimise the signs of ageing skin. Vitamin C helps reduce the appearance of fine lines and wrinkles, boosts collagen production, and protects agains future damage. Obagi-C Fx Clarifying Serum is non-comedogenic, so won't block pores. Best used as part of the Obagi-C Fx System, the Obagi-C Fx Clarifying Serum will leave your skin with a more radiant, healthy glow Did you know? Hyperpigmentation - aka dark spots or sun spots - are caused by the overproduction of melanin, which is caused by UV and photodamage, hormonal changes, and genetics.