''The main indication now for hormone therapy is hot flashes and night sweats,'' said Dr. Jacques Rossouw, a researcher for the National Heart, Lung and Blood Institute who directed the federal study, the Women's Health Initiative. ''This says that if you are older than 60, you should not take it.''

That observation needs additional study to confirm and understand it, Dr. Rossouw said. ''It's quite new and unexpected,'' he added. Because this group of older women with menopausal symptoms was not specified before the studies began, the researchers described their analysis as exploratory rather than definitive.

The new analysis was designed to answer persistent questions about hormone therapy that arose from the Women's Health Initiative.

Its two studies included 27,347 women ages 50 to 79 who were randomly assigned to receive hormones or not. One study involved women who had not had hysterectomies. They took Prempro, a drug made by Wyeth that combines estrogen and progestins. The other involved women who had had a hysterectomy and who took estrogen alone. Estrogen alone can cause cancer of the uterine lining and should not be used by women with a uterus.

The main objective of those studies was to ask whether hormone therapy could prevent heart attacks; many doctors had expected it would. Instead, Prempro increased the risk of heart attacks, strokes and breast cancer, and estrogen alone increased stroke and breast cancer risk.

Those findings were a shock to many women and their doctors, who had thought the hormones were an unmitigated good and who had considered the drugs a sort of fountain of youth. Even the name the treatment was given, hormone replacement therapy, gave that impression -- replacing hormones lost to aging. Researchers and the Food and Drug Administration no longer use the term hormone replacement therapy, but it persists in popular use.

And the studies were criticized by gynecologists, in particular, who pointed out that most of the women were long past menopause. Did the findings really apply, they asked, to younger women, in their 50s, who had just entered menopause?

To get an answer to that question, the investigators combined data from both studies and asked about health risks in the 50s, 60s and 70s.

They concluded in their new analysis that while women in their 50s taking Prempro or estrogen alone had a slightly increased risk of strokes and breast cancer, there was no increase in their risk of heart attacks.

''That is somewhat reassuring,'' Dr. Rossouw said. He suggested that if women in their 50s wanted to take hormone therapy to relieve menopause symptoms, they should be sure their blood pressure was controlled and they should have regular mammograms. But the result does not mean, Dr. Rossouw added, that if women start taking hormones in their 50s, they can safely continue into their 60s and 70s.

If the concern is heart attack risk, he said, ''we were as clear as could be that there seems to be a window of opportunity to use it in that short interval, but there is not a window of opportunity into the future,'' Dr. Rossouw said. ''And we know for sure that if you start taking it in older age, it is bad news for heart disease.''