Medical science has established a link between elevated levels of free testosterone and baldness. In some cases, baldness, or alopecia, is caused by excess amounts of adrogen hormones, including testosterone, in the body. When testosterone and baldness are linked together, the condition is called androgynous alopecia. While the condition is primarily attributed to human males, it can also be an underlying cause of female hair loss. Testosterone and baldness can also be linked in other other mammals such as chimpanzees, monkeys, gorillas, and other animal species.
One of the most commonly recognized types of alopecia is male pattern baldness. While male pattern baldness has many different possible causes, the link between free testosterone and baldness is one of the few scientifically proven theories. Many other theoretical causes of this type of baldness have been suggested, including muscle tension, tightening of the scalp, genetics, and stress.
When hair loss is associated with elevated testosterone levels, the balding effect is a symptom of the increased sensitivity of the hair follicles to the androgen hormone dihydrotestosterone (DHT). The condition is usually considered to be genetic, and the sensitive hair follicles shrink as a reaction to testosterone exposure. When the follicles shrink, they are unable to produce normal growth or support existing hair, which results in thinning hair and eventual hair loss.
Testosterone is a naturally occurring hormone in both males and females. It works in conjunction with other hormones and systems in the body to produce masculine features, sex drive, and hair growth. The bio-availability of this hormone is usually regulated by a sex hormone binding globulin (SHBG) which joins with the free testosterone, preventing it from being converted to DHT. When the production of testosterone becomes unbalanced by health problems, genetics, medication, or other factors, it can lead to elevated levels of free testosterone, and baldness can be an early symptom of the condition. Steroid use among athletes has also been attributed to causing the increased testosterone levels associated with alopecia.
Treatment for hair loss as a result of the link between testosterone and baldness is sometimes effective in the earlier stages of the condition. Such treatments may include specialized shampoos and drugs to stimulate hair growth. Other more advanced treatments have been devised, as well, including hair replacement therapy, in which healthy hair follicles are transplanted to the bald areas to stimulate new growth. These treatments are usually expensive and are not always effective.