Generally the effect of hyaluronic acid filler can be maintained for 6~12 months, the specific maintenance time is related to the type of injectables, post-operative care, etc., and there is individual variability. Hyaluronic acid injection is to inject hyaluronic acid in the form of filler into the dermal folds and depressions, such as cheeks, chin, bridge of the nose, lips, etc., so as to achieve the effect of removing wrinkles and changing the aging of the face. 1. Injection type: Hyaluronic acid has three types: large molecule, medium molecule and small molecule. Generally speaking, large molecule hyaluronic acid has a longer retention time and the best effect of filling and shaping, while small molecule hyaluronic acid has a shorter retention time. Different types of hyaluronic acid have different maintenance effects. 2. Post-operative care: Post-operative care can also affect the maintenance time of hyaluronic acid, usually the maintenance effect is shorter for older people. If you use cosmetics or other stimulating substances after the operation, and do not pay attention to keep the injection site clean and dry, etc., all of them can affect the maintenance effect. Hyaluronic acid filler should be treated in regular hospitals, and regular injections are needed to maintain good results in the long term. It is recommended that patients go to regular hospitals for consultation and standardized treatment under the guidance of doctors.