The
bisphosphonate drugs (all of them, Fosamax, Boniva,
Actonel, etc) have black box warnings required by the FDA. The FDA has also recommended that these drugs be taken 5 years or less. (my OBGYN confirmd) After that, they just make the bone hard & brittle.
There is concern about osteonecrosis of the jaw (bone death), esphogal cancer , and more recently reports of increased femur fractures in patients taking it long term.
These drugs do not "build" bone.