Glucocorticoids are widely used in medical practice mainly for suppression of the immune system. According to Selye - who named them - the endogenous molecules are very important for the adaptation to challenges, stress. They were synthesized in the 1940s. Since then numerous data have been published about their production (also locally in several organs), transportation (primarily cortisol-binding globulin) and receptors (nuclear and non-genomic effects). Although glucocorticoids are primarily under the control of the hypothalamo-pituitary-adrenocortical axis, several other molecules (especially catecholamines) may also increase their secretion. Their permissive influences are dominant, thereby they are indispensable for the effect of numerous other molecules. Thus, glucocorticoids have very diverse influence from metabolism through cardiovascular effect to bone-metabolism, affecting even the central nervous system. They are also important in metabolic syndrome. Their extensive therapeutic usage are limited by side-effects, which could be diminished - among others - with concomitant usage of the anabolic dehydroepiandrosterone.