Hylaronic acid is the active ingredient in dermal fillers. It is found in abundance in young skin. It holds onto moisture and provides both elasticity and volume with help from two other substances: collagen and elastin. Unfortunately, these break down over time and are replenished less and less as we age. This loss presents as wrinkles and diminished facial volume. When dermal fillers are injected under the skin they replace this lost volume and plump out wrinkles.