I'm on both finasteride and spiro, along with estradiol patches. The finasteride was started 6 years ago for a problem with an enlarged prostate, but I found it had other... advantages.

My urologist says I can discontinue the finasteride in about a year, once my body gives up on trying to make much testosterone. There are apparently pathways in some lower abdominal tissues like the prostate gland that synthesize testosterone and immediately reduce it to DHT, which the finasteride will continue to block.
Alas, I had already lost too much hair for finasteride to work its magic on my scalp, and even with Estrodiol I'm not gaining much back. Not enough up there for a good transplant result, so my hair comes in a box these days.