Other estrogen supplements are made of estradiol, a synthetic copy of the kind produced by human ovaries.

The Women's Health Initiative is continuing to study the use of estrogen supplements alone in women who have had hysterectomies.

Overall, estrogen supplements were found to have the best effect on women with schizophrenia.

Some benefits of using an estrogen supplement such as reduced risk of bone fractures were confirmed by these studies.

While those with both ovaries removed had double the usual risk of heart disease, the danger was not increased if they took estrogen supplements.

But experts have found that the accelerated bone loss at menopause can be completely prevented as long as a woman takes estrogen supplements.

For instance, estrogen supplements substantially relieve bone weakness in older women - and now seem effective also against other diseases.

When menopausal women took estrogen supplements, there was little change in their blood cholesterol levels, the study found.

Over the next two and a half years, 101 of them stopped menstruating and 32 began taking estrogen supplements.

She said researchers should study the possiblity of giving estrogen supplements to teen-agers who fail to have regular menstruation.