4D Hyaluronic Acid is made of 4 molecular sizes of hyaluronic acid that work throughout the skin and form a flexible film of hydration to replenish water at the surface while holding hydration deep within. Hyaluronic Acid is depleted in the skin with age, this biomimetic active retrains the skin from within to naturally restore hyaluronic acid helping improve longterm elasticity for plump and hydrated skin.