A natural and youthful lip should have undulating curves and nodular projections. A typical upper lip has three nodules: one in the center and one on each side, and one on each side of the lower lip. This anatomical structure should always be present and should not be an unattractive “sausage” lip. Normal lips should be slightly thicker on the bottom than on the top. In addition, for a young face, attractive lips should be well defined. However, with age, the aging of the lips due to the lack of tissue volume caused by the red lip shrinkage of inward curls, resulting in the following view of the length of the red lip shortened, the serious front view of the lips as thin as a pencil. In addition, the lip protrusion, mid-range ridge, and lip arch flatten over time, resulting in a lack of three-dimensionality of the lips. By injecting hyaluronic acid, the above changes can be corrected and the atrophied lips can be plumped up again.