@mmoanritkian these drugs Calcium Metabolism Modifiers and Bisphosphonate Derivativatives prevents bone from continuing to be reabsorbed which is what happens with osteopenia and osteoporosis. You correctly stated the we cannot grow new bone but we can prevent it from worsening. I’ve been on Alendronate for over 3 years with no ill effects. As a retired nurse I know a bit more than many and I’ve never questioned what was prescribed for me by a medical provider. I don’t look at the side effects until something occurs, then I start researching on my own. If you try one drug and develop a side effect you can always switch to another, it happens.