Thinning hair - MPHL/FPHL (male/female pattern hair loss) increased
androgen production together with the genetic predisposition for hair loss

Constriction of blood supply to the follicular papilla

Loss of oxygen supply to the hair follicle

Lower levels of cellular activity; lower energy production from enzyme
glucose-6-phosphate dehydrogenase (G6PDH). (Energy production is an
important component of cellular metabolism that becomes less efficient
with aging)

Lower levels of melanocyte production in the isthmus portion of the hair
follicle

Environmental factors including sun damage (photo-damage) and pollutants

Chemical services damage

Mechanical damage (brushes, hair dryers, flat irons)