Typically Restylane will last six to twelve months in non dynamic areas of the face such as naso-labial folds and less for dynamic areas such as the lips.
Greetings~ Each person varies in how long it takes for Restylane to dissolve on its own completely...it can also depend on how much was injected. I agree with Dr. Pelletiere in that it can take 12-18 months for all of it to be gone but you will notice it degrading before then. If you are unhappy with the results from previous treatment, rather than wait you should consider having it injected with Hyaluronidase to dissolve it and then start over with a clean slate. Good luck~ Dr. Grant Stevens