Methods of treatment for osteoporosis in a human or other animal subject, comprising: administering a bone-active phosphonate to said subject, at a level of at least about 0.1 LED per day of said treatment; and administering an estrogen hormone to said subject at a level of from about 0.2 to about 0.8 LED per day of said treatment. The bone-active phosphonate is preferably a bisphosphonate, or a phosphonoalkyl phosphonate.
