Hyaluronic acid is a complex sugar produced naturally by the body that lends structure and volume to the skin. The body's ability to produce hyaluronic acid diminishes with age. However, hyaluronic acid fillers are able to restore skin volume and appearance.  Also, hyaluronic acid has been used for more than 20 years for injection into arthritic joints to aids movement as well as for eye surgeries and wound repair.  Juvederm differs from other hyaluronic acid fillers in its formulation. Other hyaluronic fillers consist of tiny particles suspended in a gel whereas Juvederm consists of a smooth gel