Dehydroepiandrosterone (DHEA) and its sulfate form (DHEAS) have been the focus of considerable publicity because of their demonstrated associations with a broad range of health outcomes. Yet, knowledge about the effects of endogenous DHEA(S) on health in humans is limited and often inconclusive, largely because few of the studies have been based on prospective surveys of population-representative samples. This analysis uses a national longitudinal survey in Taiwan to investigate whether DHEAS is associated with subsequent changes (2000-2003) in functional limitations, cognitive impairment, depressive symptoms, and global self-rated health. Regression models based on this older Taiwanese sample show that among men, lower levels of DHEAS are related to declines in mobility and self-assessed health status and increases in depressive symptoms, while both low and very high levels of DHEAS are associated with poor cognitive function. There are no significant associations among women. These findings differ from those in a previous cross-sectional analysis based on the Taiwan study and underscore the importance of using prospective data to examine the effects of DHEAS on health. The evidence based on this and other longitudinal studies suggests that endogenous DHEAS is related to health outcomes for men, but not women, in both Western and non-Western populations.