What it is: A powerful vitamin C serum, now formulated with even more vitamin C, that visibly reduces fine lines and wrinkles. What it does: Kiehl's original formula, infused with 10.5% pure vitamin C, now has an additional 2% of vitamin Cg for increased potency. Vitamin Cg is a vitamin C derivative that activates once absorbed into the upper layers of the skin's surface and is used in anti-wrinkle skin care products to help reduce facial lines over time. Fragmented hyaluronic acid has also been added to this formula to help instantly smooth skin. Through clinical studies, this serum has been shown to help decrease the appearance of fine lines and wrinkles and improve skin radiance and texture, even helping to reduce the appearance of forehead lines, marionette lines and deep-set wrinkles after four weeks of regular use. How to use: Smooth on this anti-wrinkle serum morning and night to experience the warming sensation and fresh citrus scent. Cleanse skin thoroughly prior to application. Apply over your entire face, avoiding the eye area. As the formula blends into skin, you may experience a feeling of warmth. It can be used twice a day, morning and night. $140 value 3.4 oz. Dermatologist tested Safe for sensitive skin Made in the USA