THE BIG PRO: ESTROGEN AND SEX

For many women the no. 1 reason to take estrogen after menopause is to improve their sex lives. "Without it, you may soon have no sex life at all," contends Dr. Lila Nachtigall, co-author of the popular handbook Estrogen: The Facts Can Change Your Life! (HarperCollins; $11). The natural waning of estrogen in the middle years often brings physical changes that can ruin a woman's pleasure in sex. The vagina basically reverts to its prepubescent shape: narrower, shorter, dryer, less elastic, with thin walls that tear easily and are prone to infection. The libido may also dry up, if only because sex becomes painful. While many women are spared these problems in their 50s, the odds are they will strike to some degree within a decade of menopause.

Nachtigall is a fervent believer in the healing power of estrogen. "Even for women who are already in deep sexual difficulty, the therapy usually reverses the damage in only a few weeks," she writes. Estrogen creams, applied topically, are very effective at rejuvenating vaginal tissues and are probably safer than pills or patches because they put less hormone into circulation. For those whose sex drive remains stuck in low gear despite hrt, the male hormone testosterone may help, though unless dosages are watched carefully, it can cause deepening voice, growth of facial hair and other unwanted effects.

For the hormone wary there are other measures. Over-the-counter lubricants can make sex more comfortable, and nonprescription moisturizers like Replens or Gyne-Moistrin can help rehydrate dry tissues. One of the best things to keep the machinery humming is sex itself, says Dr. Wulf Utian, co-founder of the North American Menopause Society. As with aging muscles, bones and brain cells, it's a matter of use it or lose it.