The aging process depends on genetic stability, metabolic control, and resistance to stress; longevity in particular seems related to resistance to stress. Responses to stress anticipate adaptation to an unacceptable disparity between real or imagined personal experience and expectation, including adaptive stress, anxiety, and depression. However, if stress persists, it may lead to chronic diseases, ranging from inflammation and cancer to degenerative diseases. For some time, only remarkable stress was acknowledged to induce immune and vascular alterations, such as infection or hypertension. Now it is known that moderate stress independent of conventional risk factors can induce a potent alteration of health conditions and consequently shorten life quality and lifespan. Inflammation is a critical defense mechanism, that, uncontrolled, contributes to chronic conditions with inflammatory pathogenesis. Stressful life conditions turn out to induce a diffuse (systemic) pro-inflammatory status. Subclinical chronic inflammation is an important pathogenic factor in the development of metabolic syndrome, a cluster of common pathologies, including cardiovascular disease. Markers include mediators associated with endothelial activation and dysfunction. This work reports the in vitro and in vivo effects of the monoterpene AISA 5203-L on human vascular endothelial cells in reversing replicative senescence in preventing and alleviating nonpathological stress, as assessed by a functional observational battery (FOB) of 44 tests, addressing behavioral, neurological, and physiological criteria.