The general maintenance time is 6- 10 months. Different brands have different technologies, and everyone's metabolic absorption rate is different, so there will be some gaps. Before, the doctor recommended a kind of GER hyaluronic acid to me, saying that the crosslinking rate of this hyaluronic acid is almost 100%, but the crosslinking agent is less than 2%, so the maintenance time will be a little longer, about 8- 12 months.