The endogenous glucocorticoids (eGCs) group include those molecules, similar to exogenous synthetic ones in terms of chemical structure, which are synthesised in the human body: the largest amount is produced by the adrenal cortex and the rest by the skin, with a slower process. The known eCGs effects in the skin include epidermal thinning, melanogenesis impairment, inflammation suppression and erythema reduction.1-2

Cortisol is the most important among eGCs and its availability depends on the pre-receptorial regulation of the 11β-hydroxysteroid Dehydrogenase (HSD) enzymes, i.e.: 11β-HSD1 (converts cortisone to the active form, cortisol; 11β-HSD2 (catalyses the opposite reaction).