good for arthritis. Safer than HRT?
Ten women with severe osteoarthritis were given a six milligram
boron supplement, and ten a placebo, for eight weeks. Five of
the ten taking the boron supplement felt significant improvement,
compared to only one of the ten taking the placebo. The 6 milligrams
of boron were in two tablets containing 25mg of borax (sodium
tetraborate decahydrate). There were no side effects noted. 
An earlier study, had found that
supplementing a low-boron diet with three grams of boron a day
for 48 days increased beta-estradiol* and testosterone and reduced
levels of calcium and magnesium in the urine of post-menopausal
women. This suggested that the boron had reduced the rate at which
bone was being eroded.
Another study confirmed that boron supplementation appeared to
boost levels of sex hormones in both post-menopausal women (making
it a possible natural and safer alternative to HRT) and in men
of the same age.
* the most powerful form of natural oestrogen
et al. Journal of Nutritional Medicine 1990:1:127-132
 Nielsen,FH et al. Journal of the Federation of American Societies
for Experimental Biology 1987;1(5):394-97
 Nielsen,FH. Environmental Health Perspectives 1994;102(7):59-63