A substance injected into the skin to fill in gaps, add volume, and reduce the appearance of wrinkles or fine lines. It is commonly used in aesthetic procedures to improve facial contours, such as the lips, cheeks, chin, or area around the eyes. Fillers often contain ingredients such as hyaluronic acid, collagen, or calcium hydroxyapatite, which are safe and can be absorbed by the body over time. This procedure is popular because it provides fast results with a relatively short recovery time, making it a favorite choice for non-surgical facial rejuvenation.