Obagi Professional-C Serum 15% is high strength Vitamin-C serum that works to improve uneven skin tone and improve visible signs of aging. It is formulated with 15% pure L-ascorbic Acid (Vitamin-C) which provides antioxidant protection against environmental stressors, such as UV rays, which cause damage to the skin and also works to stimulate collagen production which helps to reduce the appearance of fine lines and wrinkles. It also inhibits melanin production which helps to fade dark marks and prevent new ones from forming. This serum is able to penetrate into the deeper layers of the skin and doesn’t leave an oily layer. Over time, skin texture is smoother, tone more even and skin is more radiant. Suitable for use on Normal and Combination Skin types.