TLDR The model showed that randomness accurately describes individual hair growth cycles and that synchronization can cause large fluctuations not seen in humans.
The study investigated the dynamics of human hair cycles using a follicular automaton model, which simulates the stochastic transitions of hair follicles through the growth (anagen), arrest (catagen), shedding (telogen), and latency phases. The model was based on long-term observations of ten male volunteers, both alopecic and non-alopecic. It was found that the stochastic model could accurately represent the dynamics of single follicles and the behavior of a population of independently cycling follicles. The study also explored a deterministic version of the model and found that as the number of follicles increased, the steady-state levels of follicles in different phases predicted by the deterministic equations approached those yielded by the stochastic simulations. However, only the stochastic model could reproduce the fluctuations observed in small follicle populations. When synchronization was induced, either by reducing the standard deviation or by an external signal, large-amplitude oscillations in the follicle phases occurred, which are not seen in humans but are similar to moulting in other mammals.
59 citations,
August 1998 in “International Journal of Dermatology” Genetics and hormones cause hair loss; finasteride treats it safely.
16 citations,
August 1996 in “The journal of experimental zoology/Journal of experimental zoology” Red deer hair cells offer a new way to study how hormones affect hair growth.
62 citations,
December 1994 in “Journal of Endocrinology/Journal of endocrinology” Prolactin speeds up hair growth and moulting in cashmere goats.
34 citations,
July 1993 in “The journal of investigative dermatology/Journal of investigative dermatology” Human hair growth is influenced by androgen hormones, and red deer mane follicles have similar hormone receptors.
214 citations,
March 1993 in “Archives of Dermatology” Telogen effluvium is a reversible hair loss condition that requires a detailed diagnosis and often resolves on its own.
745 citations,
February 1992 in “Trends in genetics” Hair follicles create different cell layers and proteins, controlled by various molecules.
666 citations,
September 1977 in “British Journal of Dermatology” Common baldness, also known as Androgenetic Alopecia, is caused by a combination of genetic factors and hormones called androgens.
8 citations,
February 2016 in “The American Journal of Dermatopathology” Hair transplants can make hair follicles larger and hair shafts thicker.
4 citations,
January 2015 in “International Journal of Trichology” Transplanted hair follicles can change and adapt to new areas of the body, with the immune system possibly playing a role in this adjustment.
January 2014 in “Medical Innovation of China” 
September 2013 in “中国医师杂志” Human scalp hair follicles grow well in Williams E medium, which may help with hair transplants.
9 citations,
June 2008 in “Springer eBooks” Understanding hair follicle structure is key for treating hair disorders and could help develop new treatments.
8 citations,
September 2002 in “Genes to Cells” Killing specific cells in hair follicles can lead to hair growth problems in mice.
83 citations,
April 1999 in “Dermatologic Surgery” The research found that for a typical hair density, about 11 square centimeters of donor scalp is needed to get 800 hair grafts for transplantation.
