In answer to the question "why not just go on Reclast first? Why go on Prolia at all? " -- I can only say that my doctor (endocrinologist) prescribed Reclast because my insurance company does not cover Prolia. I'm 82, I have untreated osteoporosis, and have avoided medications so far. Maybe your doctor has a particular reason for this strategy. I think that one of these meds inhibits bone-destruction, and the other boosts bone-building. But I'm not sure which is which. good luck!