Fillers represent one of the most requested minimally invasive treatment options to re-volumize the aging face. The first filler available in 1981 was bovine collagen but its short duration and potential for allergic reactions limited its widespread usage. The introduction of HA (hyaluronic acid) products in 2003 revolutionized the world of fillers. In fact, the first HA filler available was Restylane, which is still often used today. Juvederm products did not become available until 2006 ...