Formulated at the precise concentration proven to deliver maximum amounts of vitamin C to the skin, Serum 20 is now formulated with AOX+ advanced antioxidant technology, combining ferulic acid with 20% L-ascorbic acid to enhance antioxidant performance. Designed to restore and protect healthy looking skin, this lightweight and fast-absorbing serum neutralizes free radicals, defends against environmental damage, and helps prevent premature signs of aging.