Hyaluronic acid is widely distributed in all parts of the human body, especially in the dermis layer of the skin, it is one of the best substances found in nature to retain water, generally 2% of hyaluronic acid can absorb 98% of water. In childhood, the body is rich in hyaluronic acid, which is the reason why children’s skin is moist and smooth and healthy, and with age, the metabolism becomes slow, the dermis of the hyaluronic acid gradually decreases, so the older you get, the more your skin appears dry, aging, wrinkles and other phenomena. Therefore, supplementing hyaluronic acid is good for restoring the skin’s function, or it has a strong effect on the skin’s maintenance, which is good for enhancing the skin’s elasticity, and it can reduce the aging of the skin and slow down the aging. It is suitable for people of all ages who need to improve phenomena such as skin dehydration on the face or other parts of the body. Hyaluronic acid is divided into three major categories according to the degree of cross-linking: small molecule, medium molecule and large molecule hyaluronic acid, which have the functions of hydration, filler and support, respectively. It is widely used in the clinic for lip augmentation, rhinoplasty, chin augmentation, filling the apple muscle, temporal augmentation and forehead augmentation, etc. It can also eliminate the static lines of the face, including the eye fine lines, the tail lines of the eyes, the tear ducts, the bags under the eyes, the decree lines, the smile lines, etc., and it can also trim the shape of the lips, the chin, and make the nose shape higher.