Levels of most hormones decrease with aging, but some hormones remain at levels typical of those in younger adults, and some even increase. Even when hormone levels do not decline, endocrine function generally declines with age because hormone receptors become less sensitive. Although such decreased function suggests that hormone replacement therapy might be beneficial in older people, such therapy generally does not appear to reverse aging or prolong life and, in some cases (such as estrogen replacement in older women), is potentially harmful. However, ongoing research is examining the beneficial effects of providing some hormones to older people.

Last full review/revision May 2006 by John E. Morley, MB, BCh