Real-Time In Vivo Structure-Function Study of Scalp Hair Cycles: An Experimental Approach for Monitoring Living Hair Roots with a 20-Year Follow-Up

This study investigates the structure-function relationship of scalp hair cycles over a 20-year period, focusing on the effects of minoxidil and finasteride on hair regrowth. It involved 200 male participants, including 90 healthy controls and 110 with patterned hair loss. The research found that hair diameter significantly affects linear hair growth rates, with grafted follicles showing reduced growth compared to in vivo observations. Minoxidil and finasteride significantly activated anagen hair follicles within 2 months, peaking at 3 months. The study highlights the potential of using the "see-through effect" in transplantation for long-term hair cycle observation, despite challenges like reduced growth rates and aging-related changes. It emphasizes the importance of live observation of hair cycles and identifying dormancy stages, while noting limitations related to experimental models and the lifespan of human volunteers.