Dermal fillers contain hyaluronic acid (HA) ingredients that add fullness to areas thinned due to ageing. This thinning is expected in the cheeks, lips, and around the mouth. Dermal fillers are injected directly into the skin to restore quality, enhance facial features or correct asymmetry. Filler results have a duration of 9–24 months. Different types of dermal fillers are designed to treat varying signs of ageing. It is important to remember that dermal fillers are temporary treatments for facial ageing—ongoing treatments are needed for long-term results. Depending on the filler selected, they may: