I had osteopenia before I took anastozole. The first six months I took nothing for my bones because the doctors wanted to make sure that I had no side effects from it. At my 6 month evaluation, I was started on Prolia. Right before my 1 year mark, I had a BMD/DEXA scan and had full blown osteoporosis. My endocrinologist felt that the 6 months that I was not protecting my bones was significant. My last scan since Prolia had me back to osteopenia but better than before the cancer. At my 5 year mark, my oncologist did 1 Prolia because I was no longer on anastozole. Last month I started alendronate to lock in the benefits of the Prolia because without that, there could be a rebound effect where my bones would return to osteoporosis. Everyone’s treatments are different, so just stay on top of your bones.