The article examines the morphofunctional changes in rat adrenal glands during acute and chronic toxic effects of energy drinks. The experiment was conducted on 201 three-month-old white purebred male rats weighing 250–300 g. The animals were divided into control and experimental groups (acute and chronic exposure to energy drinks). Morphological and morphometric methods have established that under the influence of the energy drink, pronounced structural changes develop in the adrenal glands: significant thickening of the capsule due to connective tissue growth and fibrosis, hyperplasia and dystrophic changes in the cortical substance, a decrease in the density of secretory granules in the medullary substance, and disruptions in the ratio between the cortical and medullary layers. Signs of activation of the sympathoadrenal system and development of adaptive-compensatory processes against the background of toxic stress have been identified. The obtained data expand the understanding of the pathomorphological mechanisms of energy drinks' action on the endocrine system and can serve as a basis for developing methods for correcting identified disorders.