When it comes to hyaluronic acid injections, many people will associate it with the fact that hyaluronic acid is often contained in cosmetics. How can hyaluronic acid, which is used in cosmetics, be injected as a filler? What is the difference between the two? Many MM are curious. Then today to meet your curiosity. 1, the role of different: injections of hyaluronic acid can be used mainly for filling, shaping, wrinkle removal, once injected subcutaneously, the effect is immediate. Hyaluronic acid in cosmetics is mainly used for moisturizing, as well as increasing skin elasticity, promoting skin absorption and metabolism, etc. 2, different care: after injecting hyaluronic acid need to keep the skin at a constant temperature, should not be pressed to stimulate, need to avoid mouth. However, cosmetics containing hyaluronic acid are easy to use and do not require too much extra care. 3.It is affected by the weather: for injected hyaluronic acid, the weather does not affect its efficacy. But for topical hyaluronic acid, the dry weather will easily affect its efficacy. 4.Different molecular weight: the molecular weight of hyaluronic acid in injection is large, which is the key to decide its must be injected and has filling efficacy. The molecular weight of hyaluronic acid in cosmetics is only 1% of the injected hyaluronic acid, which can be applied to the face only. 5, maintenance time is different: hyaluronic acid is composed of a very fine molecule, and has good biocompatibility, while being able to retain the moisture in the skin, but all will be metabolized by the body, hyaluronic acid injection can generally last 6-12 months, while in cosmetics is not exact.