Hyaluronic acid (HA) is a polysaccharide that exists naturally in the dermis, whose main function is to moisturize and maintain skin firmness. Its molecules are hydrophilic and can absorb up to 1,000 times their own weight in water. Over time, the body reduces the natural production of this substance, so the skin loses hydration and volume. When injected as a dermal filler, HA restores this lost volume, attracts water to the tissues and stimulates collagen production, achieving an immediate and natural rejuvenation effect.