Have you noticed that your SkinCeuticals antioxidant serum containing biologically-active Vitamin C has changed colour? This change is expected and normal for our high concentration antioxidant serums – in fact, it is a visual indication that your SkinCeuticals Vitamin C serum is formulated in a way that will benefit your skin the most. Our Vitamin C serums feature a synergy of other active ingredients, such as Ferulic Acid, capable of maintaining the antioxidant power of Vitamin C, even in the