The World Health Organization (WHO) defines osteopenia as a bone density between 1 and 2.5 standard deviation (SD) below the bone density of a normal young adult Iqbal 2000. Osteoporosis is defined as 2.5 SD or more below that reference point Iqbal 2000. Bisphosphonates are a group of medications used to treat osteoporosis, Padget's disease of bone, and osteopenia. We report a woman who developed profound muscle weakness and pain after one dose of Risedronate (Actonel).