Stem cells are the basic cells that form the organs and tissues of our bodies. Their role is to repair damaged tissue or organs rapidly through their ability to divide without limit. Because of this ability, they are also described as the body's permanent protectors. Types of stem cells with different characteristics and sizes include fetal, embryonic, mesenchymal, induced pluripotent and adult stem cells.

Stem cell treatment is a method used to repair damaged or missing tissues or organs. Stem cells can also be multiplied in a laboratory and are used in aesthetic applications as well as in the treatment of disease. They are particularly used to address adverse effects associated with ageing.