Good, non-toxic body moisturizers do more than feel nice upon application. They protect and repair your skin barrier. Within that barrier, there are lipids (natural fats) that are responsible for hydration and firmness. This lipid barrier defends your skin from irritants and maintains natural moisture.
Unfortunately, modern society poses a variety of threats to this barrier. Free radicals from cigarette smoke, environmental pollutants, UV rays, and other toxins all damage lipids. Once compromised, the skin barrier won’t be able to do its job effectively.