In my case as an MtF transwoman, what I was referring to was the natural testosterone all my life poisoning my system and making me look more male, especially at age 59. Even FFS will not be able to cure all the damage, but I'm hopeful it can alleviate some of the disfigurement. (being overly harsh) Point, even though I won't be able to pass 100%, I do believe I'll be much happier, even with the other losses.
Best to you!
Hugs,