The newest pharmaceutical option for protecting bone density is raloxifene (brand name Evista). Raloxifene is a selective estrogen receptor modulator (SERM), which, simply stated, means it has a chemical structure similar to estrogen and attaches itself to molecules in the body where estrogen would otherwise attach. It prevents bone loss by reducing breakdown of bone much the way estrogen replacement therapy does. Postmenopausal women can expect about a 3 percent increase in bone density in the first year of taking raloxifene and 1 to 2 percent per year after that. This brings a 40 to 50 percent reduction of risk of fracture in the spine. Less than 60 percent of women will see increases in bone density with raloxifene, a markedly lower response rate than with the options described earlier, including estrogen. Raloxifene is sometimes given with a progesterone, which might improve your chances of benefiting, as well as the magnitude of your results, though there is no hard evidence of that yet.
Since raloxifene blocks estrogen, it is the best choice for postmenopausal women who can’t take estrogen, especially those fearing an increase in breast cancer risk. It is not an option for men. Although it isn’t quite as effective as other prescription options in protecting bone at the hip, and is only about half as effective in the spine, it doesn’t increase the risk of uterine cancer (as estrogen does) and may actually protect against breast cancer. (Raloxifene is very similar to tamoxifen, which has gotten a lot of press as preventing breast cancer.) It doesn’t cause breast soreness or uterine bleeding, as estrogen can.
If you can take estrogen but are hesitant to, and are wondering if this is a better alternative, note that raloxifene does not offer some of the benefits that estrogen does. Raloxifene’s effect on the heart is still unclear. Though it appears to lower cholesterol levels, it is unknown as yet whether that translates into protection against heart disease and heart attacks equivalent to estrogen’s. Raloxifene does not relieve menopausal symptoms, and can even cause or increase hot flashes. No studies have yet been completed on raloxifene’s effect on colon cancer or Alzheimer’s disease, but estrogen is known to offer protection against both. Finally, raloxifene has one of the same potential side effects as estrogen: dangerous blood clots.