Because hyaluronic acid exists in the human body itself and in the dermal tissue of human skin. It is responsible for storing moisture, increasing skin volume and making skin look plump and elastic. However, hyaluronic acid will disappear with age, which will make the skin lose its water storage capacity, gradually turn black and age, and form fine lines. You can go to a regular hospital to inject hyaluronic acid, which has no side effects on the human body, and then inject hyaluronic acid.