How long can a person hold the gains from an anabolic plus reclast?

So, I had a very shocking and discouraging comment from my endo about how long a person generally holds gains from drug therapy for OP, specifically one of the anabolics (Forteo, Tymlos, Evenity) plus reclast. She said 1-3 years. So you take drugs with, for me, probably a ton of side effects for at least 2 years and you might only benefit from it for one year???!!! If anyone has any studies on whether this is true or not, I'd love to see them. Would also like to hear people's personal experiences on this and how long they were able to keep their gains once they "locked it in" with reclast.
Rest assured, I knew this would not be a one and done type of process. But if I'm going to have my quality of life diminished from two years of taking drugs, I would hope for at least FIVE years of improvement, not ONE. ALSO, have you really made those gains? Or do you only have them while taking the drugs. Because, it took me over 15 years to lose bone density and develop OP, but apparently bone density from drugs can go away in one year, according to my endo. That just seems crazy. I was planning on just pushing through side effects, like its chemo, to get to the other side. But if I have to be on these drugs that diminish quality of life for the rest of my life with only a year off here and there then I'm probably going to push this off a few years and try to do whatever I can the natural way to stave off the merry go round of drugs that I'm apparently about to start. I'm just flabbergasted. And I know, for those of you who haven't gotten seriously ill from meds where the cure IS literally worse than the disease for you, it is impossible for you to understand/empathise with. But I have. And it sucks. So please, is there anyone on here or do you know of anyone who has made it three or more years before having to go back on these drugs? Or know of long term studies showing how long people keep gains, I would appreciate it. Please answer only the question given. I don't need a lecture right now. Thank you!