During normal biochemical processes throughout the body including the skin, there are damaging molecules produced called free radicals. These free radicals are very damaging to DNA and also other components of the cells. These are normal byproducts of the chemical reactions in the skin, but free radicals can also be produced in response to environmental hazards and pollutants such as smog, pollution, cigarette smoke, and radiation. Antioxidants are molecules that act like little sponges to soak up the free radicals so they do not damage the DNA and cellular components. Even vitamins can serve as good antioxidants such as vitamin A, C, and E. The key with any antioxidant that you are using to treat the skin is that it must be able to penetrate the outer layer of skin and get down into the skin to work. We can identify many agents that act as antioxidants but if they can't get into the skin to work, then they really render themselves useless. Many companies are trying to optimize the creams that the antioxidants are in to allow them to penetrate the skin and work better.