Stable, recrystallization-resistant invert emulsions, suited, e.g., for preventing/treating the signs of chronological or actinic skin aging and for preventing/treating atrophy of the skin or mucous membranes, comprise a cosmetically/therapeutically effective amount of DHEA and/or chemical and/or biological precursor or derivative thereof, such invert emulsions also comprising a glycolic or hydroglycolic dispersed hydrophilic phase, a lipophilic continuous phase and an emulsifier having an HLB ranging from 2 to 7.