Hyaluronic acid (HA) is a naturally occurring substance that is already found in skin. Dermal fillers are temporary gel-like substances made of HA that are injected beneath the skin surface, typically in the lower half of the face. These are used to improve facial symmetry and smooth/soften lines around the nose and mouth (nasolabial folds, vertical lip lines and marionette lines). They also enhance facial contours by restoring lost volume of sunken cheeks and can be used for plumping and enhancing thinning lips. Effects are immediately visible and can lasts from 6 months to 6 years.