Hi @rn40. You do not state whether you had gains from Evenity or not. If you had gains the basic idea is that you have to take an anti-resorptive med to keep those gains. Evenity is not known to cause a terrible rebound effect like Prolia but you do still lose your gains in bone density without a follow up. It's unclear to me how long that takes but I'm guessing it starts pretty soon after you stop and continues until all those gains are gone.

There was a major study showing that Evenity followed by Fosamax helped prevent fractures. It is a standard protocol.
Perhaps your doc mixed up what you need as a follow up to Prolia? Fosamax is not thought to be strong enough to be a good option to follow Prolia. Reclast is thought to be strong enough for that situation. But for follow up to Evenity, Fosamax should be fine.
I don't recall seeing anywhere that Fosamax could not be used as an Evenity follow up.