Role of Androgen Hormones in Male Balding

• Testosterone vs. DHT
• Transgender Hormone Therapy

Research indicates that the androgen testosterone and related sex hormones play an important role in male androgenetic hair loss (AGA, or common balding). Most hair follicles possess androgen hormone receptors that influence hair growth in varying degrees. Notable exceptions are eyelashes and eyebrows, which are androgen-independent.^{(22, 81)}

History of Sex Hormones and Hair

Evidence supporting testosterone’s role in hair loss dates back at least as far as the ancient Greeks, when Hippocrates observed that men who had been castrated did not go bald. Modern science has shown that sex hormones stimulate hair growth on the face, trunk, underarm, and groin areas following puberty are also involved in common balding.⁽²²⁾

Testosterone vs. DHT

However, elevated levels of testosterone are not required to trigger male AGA. In fact, studies have not consistently found that levels of testosterone in the blood are higher in balding men. Men with normal circulating levels of androgens also develop AGA, so testosterone levels by themselves do not appear to be the only cause of male baldness.⁽²²⁾

Scientific studies point to the hormone dihydrotestosterone (DHT) as having a greater role in AGA than elevated levels of testosterone. This does not mean that testosterone is unimportant—DHT can only be metabolized from testosterone, with the help of an enzyme.⁽³⁾

Transgender Hormone Therapy

People transitioning from female to male require testosterone hormone therapy. Unfortunately, research shows that this hormone therapy for transgender men increases the risk of hair loss.⁽³²²⁾