Isoflavones are water-soluble chemicals found in many plants. Ipriflavone is a semisynthetic version of an isoflavone found in soy.

Soy isoflavones have effects in the body somewhat similar to those of estrogen. This should be beneficial, but it is possible that soy could present some of the risks of estrogen, as well. In 1969, a research project was initiated to manufacture a type of isoflavone that would possess the bone-stimulating effects of estrogen without any estrogen-like activity elsewhere in the body. Such a product would help prevent osteoporosis, but cause no other health risks.

Ipriflavone was the result. After 7 successful years of experiments with animals, human research was started in 1981. Today, ipriflavone is available in over 22 countries and in most drugstores in the United States as a nonprescription dietary supplement. It is an accepted treatment for osteoporosis in Italy, Turkey, and Japan.

According to all but one study, ipriflavone combined with calcium can slow and perhaps slightly reverse bone breakdown. It also seems to help reduce the pain of fractures caused by osteoporosis. However, since it does not appear to have any estrogenic effects anywhere else in the body, it shouldn't increase the risk of breast or uterine cancer. On the other hand, it won't reduce the hot flashes, night sweats, mood changes, or vaginal dryness of menopause, nor prevent heart disease.

Note: A recent, large study found that ipriflavone might reduce white blood cell count in some individuals. See Safety Issues for more information.

Ipriflavone is not an essential nutrient and is not found in food. It must be taken as a supplement.