Individual pharmacokinetic profiles of captopril and capoten depend on adaptation reactions of the organism and variants of autonomic regulations of functions. Maximum bioavailability and peak concentrations of captopril in blood plasma were observed during phenotypically determined physiological adaptation reactions of the general adaptation syndrome (“training” and “zone of mild activation”) and decreased during reactions of “enhanced activation” and “hyperactivation” The observed relationships can be explained by the existing gradient of sympathetic influences in the regulation of variants of adaptation reactions.