During the first week of embryonic life after fertilization. Embryo at blastocyst stage compose of stem cells. Trillion, trillion of cells all look alike. These cells will differentiate to difference kind of cells, tissue, and organ and finally embryo and fetus. Stem cell mainly differentiate to become tissue and organ but part of stem cell stay dormant and persist there life time. Stem cell will activate and differentiate when needed. For example, cut wound on skin will stimulate stem cell to differentiate to cell that produce collagen and epithelial cell to heal the wound.
Hair follicle have 2 kind of stem cell. First is epithelial stem cell or germ cell will differentiate to hair matrix and produce hair. Second is mesenchymal stem cell (msc) which is surround the hair follicle in dermal sheath outside basement membrane of hair follicle. This mesenchymal stem cell will differentiate to hair papilla and control all metabolic need during producing hair. Mesenchymal stem cell after become hair papilla also controlled by hormone DHT.
For stem cell which is DHT positive activity promote hair growth. DHT negative activity will stop hair growth produce baldness. Hair transplant if replace DHT negative activity with DHT positive activity stem cell then new hair will have no chance to get destroy from DHT. New hair will stay fuller and forever.