Abstract: The present invention provides methods of increasing bone mass in a human or other animal subject afflicted with osteoporosis, comprising a thirty(30)-day treatment period, comprised of a parathyroid hormone administration regimen and a bisphosphonate administration regimen, wherein(a) said parathyroid hormone administration regimen comprises the administration to said subject of parathyroid hormone at one or more level of from about 4 IU/kg per day to about 15 IU/kg per day that said parathyroid hormone is administered, provided that said parathyroid hormone is administered at least one day every seven days of every said thirty(30)-day treatment periods; and wherein(b) said bisphosphonate administration regimen comprises the administration to said subject of a bisphosphonate at a level of from about 0.0005 mgP/kg to about 1.0 mgP/kg per day that said bisphosphonate is administered, provided that said bisphosphonate is administered at least 1 day of every said thirty(30)-day treatment period.