Pills containing estrogen and progesterone do not improve the quality of life for most women who have gone through menopause, erasing the last reason many women had for taking the once-popular drugs, a major government study reported yesterday.

The federally funded Women's Health Initiative last summer issued the landmark conclusion that the risks of hormone therapy outweighed any protection from osteoporosis and other diseases. In this new study, the initiative produced convincing evidence that for most women the hormones also fail to improve their sense of vitality, memory, mental health, sleep, sexual satisfaction or other measures of well-being.

"We found almost imperceptible differences on all the measures we looked at," said Jennifer Hays of the Baylor College of Medicine in Houston, who coordinated the new research. "For the average woman, it does not have much of an effect."

The only evidence of possible benefit was for younger women who had trouble sleeping because of severe hot flashes and night sweats. Those women -- 10 percent to 20 percent of those using hormones -- seemed to get some relief, but it appeared to be minimal and temporary, lasting only for the first year after menopause, Hays said.

The findings contradict long-held popular conceptions that led women to take hormones for years to alleviate the short-term discomfort and long-term health threat from menopause. For millions of women agonizing over whether to take hormones, the new findings should make their decision to stop easier, experts said.

"I think this is another bit of evidence that really now suggests that there's absolutely no reason for women who feel well to take hormones," said Deborah Grady of the University of California at San Francisco.

The Women's Health Initiative, a massive National Institutes of Health project aimed at studying a range of medical issues by following thousands of women for many years, shocked women and doctors last July. The study concluded that any health benefit the hormone combination offered, such as protecting against the bone-thinning disease osteoporosis and colon cancer, was outweighed by an increased risk for heart attacks, strokes, blood clots and breast cancer.

The announcement created widespread anxiety and confusion. Millions of women stopped taking the hormones, but some continued, or quickly resumed, because of debilitating problems such as hot flashes, night sweats and vaginal dryness. Others were uncertain what to do because of the common belief that the hormones could significantly improve a woman's quality of life by boosting her energy, improving her memory, invigorating her sex life and by alleviating the troubling symptoms.

Previous research produced mixed results on the hormones' usefulness for such purposes. The new analysis was designed to provide definitive evidence by studying the largest number of women ever in the best-designed format.

The study involved 16,608 women ages 50 to 79, half of whom took the hormone combination Prempro while the other half took a placebo. All of them answered detailed questions about their physical, emotional and cognitive well-being.

Overall, the study found no indication that women would notice a difference in their lives from taking the hormones, according to a report that will be published in the May 8 issue of the New England Journal of Medicine. Officials released the study early to help women struggling to decide what to do.

Since most of the women in the study were not reporting problems when the study began, the researchers did a more detailed analysis of data from more than 2,000 women who had reported moderate to severe symptoms and found some indication those taking hormones felt better.

But the improvement was marginal, and even those who did seem to benefit would probably have started to feel better without hormones after about a year, Hays said. In fact, data on 1,500 women who were followed for three years showed that the benefit disappeared.

"I think this is reassuring news for women who stopped taking hormones this summer because of health concerns. Even for women who are having hot flashes, our findings suggest they should hang in there," Hays said.

Hays acknowledged, however, that the study did not include women who were suffering the most severe problems, because those women were so badly affected they would not volunteer for a study that might end up substituting dummy pills for their hormones. "I would not apply our results to those women," Hays said.

Wyeth Pharmaceuticals, which makes Prempro, said the findings were not surprising because most of the women in the study were not suffering from debilitating symptoms.

"We think the findings are not likely to have any clinical meaning for symptomatic menopausal women, and therefore they should be interpreted with caution," said spokeswoman Natalie deVane. "Hormone therapy is indicated for the relief of menopausal symptoms such as hot flashes or night sweats. These can be extremely disturbing. So for those women, hormone therapy is really the only thing indicated to provide relief."

Cynthia Pearson of the National Women's Health Network said the new findings show that "hormone manufacturers have been skillfully and effectively skirting drug promotion restrictions for decades, persuading women and clinicians that hormone therapy will improve the mental health, sex lives and overall well-being of older women."