Testosterone is the primary male sex hormone and is involved in several bodily processes such as libido, muscle building and even cognitive functions, according to Harvard University. One other process that testosterone is thought to be linked to is hair loss. If you have just noticed that your hair may be thinning or if you have been experiencing it for a while, becoming familiar with the hormonal processes that cause hair loss can help you treat it.
Cause of Hair Loss
According to the American Hair Loss Association, 95 percent of hair loss cases in men are caused by hormonal androgenic alopecia. Dr. Glenn Charles, hair restoration surgeon and senior physician member of the American Hair Loss Association, reports that dihydrotestosterone (DHT), which is a derivative of testosterone, actually causes androgenic alopecia. In females, the cause of hair loss is somewhat less clear, but excess androgenic male hormones like testosterone and DHT are thought to play a major role.
Function of Testosterone in Hair Loss
Contrary to popular belief, testosterone does not directly cause hair loss. Androgenic alopecia is caused by two things: a predisposition to hair loss and the presence of dihydrotestosterone.
According to the American Hair Loss Association, having hair follicles that are genetically predisposed and prone to pattern baldness and thinning is the "cause" of why certain hairs on your head can fall out.
Testosterone can convert naturally to dihydrotestosterone via the 5-alpha-reductase. Dr. Glenn Charles reports that you may have certain hairs that are predisposed to shed and thin when certain levels of dihydrotestosterone are reached. DHT attacks hair follicles that are not genetically programmed to withstand the hormone and progressively thins them.
Misconceptions
It is a common misconception, but high testosterone levels in men do not cause hair loss, according to Dr. Robert Bernstein, elite hair restoration physician and professor of dermatology at Columbia University. Bernstein explains that hair loss occurs and varies based on how sensitive your hair follicles are to dihydrotestosterone. Dr. Bernstein notes that if hair loss was simply caused by testosterone, you could expect that body hair as well as scalp hair would all fall out. Body hair is most often completely resistant to DHT and generally grows faster when testosterone levels are high.
FDA-Approved Treatments
As of 2010, there are two FDA-approved treatments for dihydrotestosterone androgenic hair loss: finasteride and minoxidil. Finasteride is an oral treatment that is only for men and reduces DHT levels by up to 60 percent, according to the American Hair Loss Association. They regard finasteride as the "first line of attack" for men trying to decrease hair loss. Minoxidil is the other FDA-approved hair loss solution. It is a topical treatment that can be used by both men and women. It is thought to promote hair growth by increasing blood flow to the scalp. Unlike finasteride, it does not address the hormonal component to hair loss.
Warning
Consult your physician or dermatologist before taking or using any hair loss treatments. If you are losing an abnormally high amount of hairs per day--well in excess of 100 hairs--this may be a sign of an underlying medical condition. Since finasteride lowers DHT levels, you may experience sexual side effects. Dr. Glenn Charles states that 2 percent of users report a loss of libido and erectile dysfunction.
References
- Charles Medical Group: Hair Transplant Restoration Facts
- Bernstein Medical: Hair Loss Myths
- American Hair Loss Association: Men's Hair Loss / Introduction
- American Hair Loss Association: Men's Hair Loss / Treatment
- Charles Medical Group: FDA Approved Options to Get Your Hair Back
- Harvard Medical School: Testosterone May Improve Mental Function
