Biochemical Roles of Testosterone and Epitestosterone to 5α-Reductase as Indicators of Male-Pattern Baldness

The study from January 2001 analyzed the correlation between testosterone, epitestosterone, dihydrotestosterone (DHT), and 5α-reductase in hair to predict male-pattern baldness (MPB). It included 19 balding fathers (aged 28–55), 16 of their sons (aged 8–16), and 55 age-matched nonbalding control subjects. The results showed a significantly higher testosterone to epitestosterone ratio in the hair of balding fathers (mean 46.41, p<0.001) and their sons (mean 35.83, p<0.001) compared to nonbalding controls (mean 9.17 and 10.47, respectively). This suggests that a high testosterone to epitestosterone ratio is characteristic of MPB and that epitestosterone may inhibit 5α-reductase, potentially reducing DHT levels in hair follicles. The study concluded that measuring these steroids in hair could help predict MPB at a young age and assist in prevention and treatment by managing steroid hormone balance.