Obagi Professional-C Serum 20% is a high-performance Vitamin-C serum recommended for leathery, sun-damaged skin that has visible signs of aging. It works to improve uneven skin tone and give skin a more youthful appearance. This serum is formulated with a high concentration of pure L-ascorbic Acid (Vitamin-C) at 20%. This high percentage is beneficial for Oily skin types as it has anti-bacterial effects and can assist with the prevention and treatment of breakouts. It also 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 lines and wrinkles. Vitamin-C also helps with pigmentation by inhibiting 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. Recommended for use on Oily or Mature, Sun-damaged Skin types.