Skinceuticals Phloretin CF Serum 30ml Antioxidant Serum for All Skin Types It contains a very effective and unique molecular composition that helps protect different cell types deep within the skin from attacks and damage due to environmental effects. It strengthens the structure of the skin by supporting collagen and elastin levels. It helps make the skin firmer, more radiant and visibly younger-looking. How to use: After cleansing the skin, take 4-5 drops of serum into your palm. Apply to dry face, neck and decollete with your fingertips. If irritation due to Vitamin C occurs, discontinue the application until the skin improves.