This study was implemented to test the Episkin model of reconstructed epidermis in the evaluation of the efficacy of cosmetic or dermopharmaceutical products on cutaneous energy metabolism. The energy metabolism is evaluated by measuring the concentration of intracellular ATP by a method using an ultrasensitive bioluminescent reaction. The work presented compares results obtained in reconstructed epithelium and monolayer primary cultures of human keratinocytes. After application of a hydrosoluble product, the increase in intracellular ATP is identical in a monolayer culture of keratinocytes (+239 +/- 18% versus control) and in Episkin (+248 +/- 21% versus control). An emulsion was also tested on the two models. It is only possible to test the emulsion at a dilution of under 0.05% on a keratinocyte culture, and this means that the real efficacy of the product is underestimated (+145 +/- 18% versus control). The three-dimensional model enables the application of the undiluted emulsion, and the results show an increase in intracellular ATP of +420 +/- 80% versus control: products in final formulation can be tested in normal conditions of use.