In the plastic surgery market in Europe, America, Hong Kong and Taiwan, collagen and hyaluronic acid are two main components of dermal tissue, and their contents will decrease with age, resulting in skin aging, wrinkles, roughness and uneven skin color. The principle of filling plastic project is to supplement these two missing components. However, at present, collagen is mainly filled with materials extracted from animals, and there are problems such as animal-derived diseases and heterogeneous protein allergy, so hyaluronic acid which can be obtained by artificial synthesis becomes an ideal filling material. Its greatest advantage is that it has no antigenicity, that is, there will be no foreign body reaction and no zoonosis. Hyaluronic acid's biggest function lies in moisturizing, keeping skin elastic, locking water molecules, moisturizing and lubricating tissues, which are found in many high-end cosmetics. Hyaluronic acid for injection is a purified component. After injection, it will fuse with the original hyaluronic acid in the body, the skin will swell, and wrinkles will flatten and swell. Hyaluronic acid will be gradually absorbed by the human body over time. The validity period is about 4 to 6 months. Hyaluronic acid will be gradually absorbed by the human body over time, which is a reason that many plastic surgeons think is extremely safe. If you are not satisfied with the injection, you can recover after a period of time without any harm to your body, because the substance itself is a component of the skin and will be excreted with metabolism. Liu Feng pointed out. However, hyaluronic acid filling is time-sensitive. According to Luo Shengkang, the currently approved Risperidone is valid for about 4 to 6 months, after which it will be restored to its original state.