Autumn, There is no universally excepted amount of time that you would need to be on HRT before FSS. Most surgeons would like to see you be on hormone therapy for about a year before surgery, but there are many exceptions. First, FFS does not mean the same thing for ever patient. Some patients have many procedures, some patients only have 1 or 2. If you are only going to have a feminizing rhinoplasty there is no reason that you have to be on hormones. Some patients cannot take hormones for medical reasons, like a blood clotting disorder. Hormone therapy can improve your skin quality and may add some volume back to your face. When performing cheek augmentation for patients we would ideally like to see a year of hormone therapy so that we know the volume is stable. The most important thing we look for before surgery, though, is for a patient to demonstrate a consistent set of providers providing for their medical needs in an appropriate and coordinated fashion. Dr. Rolfes