Hormone replacement therapy (HRT) is one way to prevent osteoporosis in women. HRT does have side effects, including an increased risk of blood clots and gallbladder and heart diseases. Taking HRT as a combination therapy - estrogen with medroxyprogesterone acetate (such as Prempro®) - for several years or more may increase your risk of breast cancer. All combination HRT regimens can cause irregular vaginal bleeding, particularly during the first year of use. More study is needed to learn if estrogen-only therapy increases your risk of breast cancer.

Other prescription drugs can help slow bone loss and may even increase bone density over time. They include:

  • Bisphosphonates are a group of drugs that can inhibit bone breakdown, preserve bone mass and even increase bone density in the spine and hips. The most well-known of these drugs is alendronate (Fosamax®). Studies show it may reduce your risk of hip and spine fractures by about 50 percent. The drug etidronate (Didronel®) is also sometimes prescribed to help prevent bone loss. Bisphosphonates may be especially beneficial for men, young people and those with steroid-induced osteoporosis. They are also used to prevent osteoporosis in people who require long-term steroid treatment for a disease, such as asthma or arthritis. Side effects can include nausea, abdominal pain and irritation of the esophagus.
  • Raloxifene is a type of selective estrogen receptor modulator (SERMs). Raloxifene imitates estrogen's good effects on bone density without some of the increased cancer risks. Hot flashes are a common side effect of raloxifene. Anyone with a history of blood clots should not use this drug.
  • Calcitonin is produced by the thyroid gland. It may slow bone loss and prevent spine fractures, although it may not prevent hip fractures. It is given as a nasal spray, and about 12 percent of those who use it develop nasal irritation. It is usually used by those who are at high risk of fracture but who cannot take estrogen or bisphosphonates.
  • Tamoxifen is a synthetic hormone that has been used to treat breast cancer for almost 20 years. Although tamoxifen blocks estrogen's effect on breast tissue, it has an estrogen-like effect on other cells in your body, including bone cells. However, tamoxifen may have serious side effects.
  • Statins are a class of drugs that are commonly used to lower cholesterol levels. Statins include pravastatin (Pravachol®),   fluvastatin (Lescol®),   simvastatin (Zocor®),   lovastatin (Mevacor®) and atorvastatin (Lipitor®). Some studies have shown that women who take statins for at least a year may also reduce their risk of bone fractures, but other studies contradict these findings. Because research is ongoing, the drugs are not routinely prescribed for osteoporosis. Side effects include potential reversible liver damage and rarely muscle inflammation.