*3.2. Tissue Distribution*

Measurable levels of Humanin are detectable in plasma, seminal fluid, and cerebrospinal fluid. A circulating Humanin pool has been demonstrated in various tissues of the human body, including hypothalamus, liver, heart, kidney, colon, testes, vasculature, and skeletal muscle [23–28]. Circulating plasma levels of Humanin decline with age in both humans and mice [29]. Demonstrating a proportional relationship between Humanin levels and human aging is of particular importance, as this could promote research that aims to boost Humanin levels and thereby delay aging in humans.
