In order to better define the kinetics of the adrenal androgens in hyperprolactinemic states, we have studied 10 patients suspected of having a pituitary prolactinoma. Compared with the levels in 10 healthy control women (normal range: N), no significant differences in the mean (+/- standard error) plasma concentrations of cortisol (F), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DS), androstenedione (A), and testosterone (T) were found: F, 22.7 +/- 2.6 micrograms/100 ml (N = 10 to 25); DHEA, 7.5 +/- 1.4 ng/ml (N = 3.0 to 12.5); DS, 1.7 +/- 0.3 micrograms/ml (N = 1.1 to 3.6); A, 2.2 +/- 0.3 ng/ml (N = 0.5 to 3.5); T, 30.5 +/- 6.4 micrograms/100 ml (N = 20 to 80). Using constant infusions of unlabeled steroid, the metabolic clearance rates (MCR) of the adrenal androgens DHEA and DS were found to be 1282.6 +/- 342.6 liters/day and 5.6 +/- 1.4 liters/day, respectively, which were no different from the MRC of 1689.4 +/- 364.2 liters/day and 6.8 +/- 1.9 liters/day, respectively, found in the normal control women. Medical therapy with a dopaminergic agent in three of these patients reduced mean circulating levels of prolactin from 81.1 +/- 4.7 ng/ml to less than 15 ng/ml but did not change any of our results. It is concluded that, in the study group, hyperprolactinemia exerted minimal trophic effects on the production rates of adrenal androgens.