Researchers say the findings mean that women who have had breast cancer should avoid hormones and find other ways to treat menopause.
Following the isolation of the "female principle" in the 20's, doctors began to recommend estrogen to treat the symptoms of infertility and, most notably, menopause.
How does one decide whether to treat menopause, and if so, how?
Gamma oryzanol is also often promoted for treating menopause, but it is unclear how it would work for this use.
She has been called a leader in understanding and treating perimenopause and menopause.
The use of estrogen to treat menopause took off in 1966, when a doctor, Robert Wilson, wrote the best-selling book "Feminine Forever" and flew across the country promoting it.
Just as the earlier book emphasized pregnancy as a healthy process rather than an illness, the new book treats menopause as a natural stage of life.
In combination with other herbs, heather is used for treating diabetes, menstrual discomfort, menopause, and nervous exhaustion.
Many other medical doctors, though perhaps less knowledgeable about natural hormones, are dissatisfied with the "approved" methods of treating menopause, because these so often prove to be unpleasant and possibly dangerous.
These foals are the offspring of horses who have been impregnated so that their urine can be used to make Premarin, a drug used to treat menopause.