Restylane lip injections tend to last around 9 to 12 months on average. You can turn to regular maintenance injections as needed to sustain the results of your procedure. If you ever decide you are unhappy with the results, hyaluronic acid fillers can also be reversed with the use of an enzyme called hyaluronidase. We have yet to have to reverse lip filler on a single patient. Our patients love their results.