In principle, there is no permanent hyaluronic acid. Usually, the metabolic time of hyaluronic acid is 1 year, which refers to the metabolic time in vitro. After injection into the body, such as Risperidone 2, the metabolism is basically completed in 9 months. But it depends on the injection site. For example, some people may not finish metabolism for several years, because the cells in the silkworm area grow into hyaluronic acid, and the speed of metabolism will be very slow, and it may take several years to completely metabolize, and the effect will be relatively longer. The permanent hyaluronic acid that is often mentioned now is probably long-acting hyaluronic acid, such as Qiao Yadeng No.5 hyaluronic acid, which is commonly used in breast enhancement and hip plastic surgery abroad. Their own molecular weight is relatively large, and the time for this macromolecule hyaluronic acid to metabolize itself will reach one and a half years or even longer. If cells grow into hyaluronic acid, the metabolic time will be longer.