6 citations,
November 2013 in “International Journal of Radiation Biology” Gamma-rays exposure during the resting phase of hair growth can damage hair regeneration and color in mice.
Curly hair may be caused by a muscle contraction, and muscle relaxants might help treat it.
40 citations,
February 1990 in “Journal of The American Academy of Dermatology” A 17-year-old developed woolly hair nevus in adolescence, which is unusual, and over time the hair darkened and straightened slightly, but microscopic changes persisted.
6 citations,
April 1996 in “Journal of histochemistry and cytochemistry/The journal of histochemistry and cytochemistry” TGF-alpha is present in sheep and ferret skin and may affect hair growth without directly stimulating cell proliferation.
4 citations,
January 2018 in “Advances in Experimental Medicine and Biology” The document concludes that hair follicles have a complex environment and our understanding of it is growing, but there are limitations when applying animal study findings to humans.