The Hair Cycle on the Human Thigh and Upper Arm

In a study conducted 38 years ago involving 11 females and 9 males aged 20-30, researchers found that hair follicle density on the thigh and upper arm was similar between genders. However, males had significantly longer hair on the thigh, with an average definitive hair length three times that of females, due to a longer anagen phase (54 days in males vs. 22 days in females) and a faster growth rate. The complete hair cycle on the thigh was also longer in males (151 days) compared to females (84 days). On the upper arm, the difference was less pronounced, with males having a 1.42 times longer hair length and a 1.27 times longer anagen phase than females. The complete hair cycle on the upper arm was similar between genders (108 days in males vs. 106 days in females). The use of oral contraceptives in females did not significantly affect any of the measured parameters.