A method of identifying or evaluating skin-care actives that improve the metabolism of a skin cell. The method includes contacting cells with a stressor and a test agent and determining a response of the cells to the stressor and test agent, based on the change in metabolic indicators associated with glycolysis and/or oxidative phosphylation. The test agent may be identified as a skin-care active when the oxidative phosphorylation and/or glycolysis response corresponds to an improvement in cellular metabolism.