Although hair loss is common, it is often considered an undesirable outcome. Another popular opinion is that body hair can be just as unpleasant. Hair growth undergoes a cycle of rest and growth, where hair follicle stem cells (HFSCs) either remain quiescent or become transiently proliferative.

The methods developed by Dr. Hsu to modulate hair growth by controlling hair follicle stem cell (HFSC) activation could lead to hair loss treatments and hair removal products. Findings from the Hsu lab suggest that without noradrenaline signaling, HFSCs enter deep quiescence, while sympathetic nerve activation of HFSCs directs the formation of a sympathetic nerve niche, which controls hair follicle regeneration in adults. Exposure to cold and topical application of a beta-2-adrenergic receptor agonist (procaterol) increases sympathetic nerve activity in the niche and promotes hair regrowth.

Interestingly, the Hsu Lab found that fibroblast growth factor 18 (FGF18) is a key player in promoting the quiescence of HFSCs, pointing to the modulation of FGF18 as an alternative method to induce or repress hair growth. This work reveals mechanisms involved in hair follicle stem cell modulation, which opens the door to developing products to prevent hair growth or to promote hair regrowth. Both can then be exploited for innovative product development.