Despite more than a hundred years of professional hair research, and substa
ntial recent progress in unravelling the molecular controls of hair follicl
e morphogenesis, the chronobiological control system that cyclically drives
the hair follicle through dramatic remodelling processes between phases of
growth (anagen), regression (catagen), and relative resting (telogen) have
remained disappointingly obscure. In view of the vast literature that has
become available over the past decades on numerous genetic, biochemical, ce
llular and pharmacological aspects of hair growth control under physiologic
al and pathological conditions, it is astounding how comparatively few rese
archers in the field have published theoretical concepts that explore how h
air follicle cycling might be controlled. Since this question is at the ver
y heart of basic and clinically applied hair biology, it deserves a much mo
re systematic and serious public exploration, which the following contribut
ions are designed to stimulate.