With over 40 million treatments worldwide and counting, the Restylane line of hyaluronic acid fillers provides natural-looking results. Restylane is a clear gel formulation of hyaluronic acid specifically formulated to act like your body's own naturally produced hyaluronic acid. Hyaluronic acids, which are sugars naturally found in the skin that help provide hydration, fullness and elasticity. Restylane injectables last from 6-18 months depending on the product choice.