If you have noticed your hair starting to thin or recede, it’s easy to stress over what’s causing it to happen. Is it stress? A bad diet? Unlucky genetics? Or is it a lifestyle factor you can fix through a change in behavior?
The reality is that hair loss in men is primarily caused by a combination of genetic factors and a male steroid hormone called dihydrotestosterone (DHT), which can bind to receptors throughout your scalp and interrupt your natural hair growth cycle.
DHT can seem complicated, but its role in hair loss is fairly easy to understand once you have a basic knowledge of how your body produces DHT, as well as the damaging effects that DHT can have on your hair follicles if you’re genetically susceptible to its effects.
What is DHT?
DHT, or dihydrotestosterone, is a type of androgen hormone that’s produced by your body as a byproduct of testosterone.
Androgens are hormones that produce male characteristics. They’re responsible for maintaining certain aspects of your sexual health, as well as your male secondary sex characteristics, which includes features such as a deep voice, as well as your body hair and bone structure.
Although testosterone is your body’s primary male sex hormone, DHT also plays a major role in numerous vital functions within your body. Prior to birth, it helps to promote proper development of your genitals, and during puberty, it’s responsible for your facial and body hair.
Your body produces DHT as a byproduct of testosterone through the 5α reductase enzyme, an enzyme that converts a small percentage of your testosterone into DHT in bodily tissue such as your skin, liver, prostate and hair follicles.
In most men, testosterone is much more abundant than DHT. According to research, the typical level of DHT in your bloodstream is only around 10 percent of your level of testosterone. However, because of its potency, DHT can have significant effects within your body, even if the total amount of this hormone that circulates in your bloodstream is relatively small.
DHT is The Enemy of Your Hair
DHT can attach to receptors referred to as androgen receptors, which are found inside your hair follicles. When DHT attaches to these receptors, it can cause them to undergo a process referred to as “miniaturization,” in which the hair follicles gradually shrink, wither and eventually stop growing new hairs.
When DHT miniaturizes your hair follicles, it shortens the anagen phase and prevents your hair from growing properly. Over time, hairs affected by DHT become thinner and shorter, eventually resulting in hair that’s unable to penetrate through the outermost layer of your skin.
As your hair becomes affected by DHT, you may notice that certain areas of your scalp begin to look thinner than before.
This process usually begins at your hairline and crown, resulting in the classic receding hairline that many men notice as their first sign of hair loss.
Interestingly, DHT is also an important hormone for hair in other areas of the body, meaning the same hormone that’s responsible for male pattern baldness is also responsible for the growth of hair on your chest, back and legs.
DHT, Genetics and Hair Loss in Men
So, if DHT is responsible for male pattern baldness and all men produce DHT as a byproduct of testosterone, why do some men go bald early in life while others are able to effortlessly maintain a full head of hair well into old age?
Just like your genes play a major role in determining your height, hair color, eye color and other physical characteristics, genetic factors have a massive influence on how susceptible you are to male pattern baldness.
After all, male pattern baldness is commonly referred to as androgenetic alopecia — a word that is made by fusing together “androgenic” and “genetic.”
Experts believe that some men go bald faster than others due to a genetic predisposition to the effects of androgens such as DHT.
In other words, some men appear to have hair follicles that are more sensitive to the effects of DHT than others, meaning they miniaturize and stop growing new hairs faster when DHT binds to receptors in the scalp.
Research also suggests that men affected by male pattern baldness tend to have higher levels of DHT than their peers, as well as greater concentrations of androgen receptors in the scalp.
This means that if you’re very susceptible to hair loss, you may not just be more sensitive to the effects of DHT than your peers — your body may also be more prone to converting testosterone into DHT, particularly in your hair follicles.
DHT, Menopause and Hair Loss in Women
It’s worth noting that the effects of DHT on hair follicles don’t only occur in men. Women are also affected by DHT. In fact, many women start to develop some signs of DHT-related hair loss after middle age, particularly as they enter into menopause.
Because menopause affects your production of several hormones, it can often trigger hormonal hair loss in women.
During menopause, your body’s production of estrogens and progestins can decline. Alongside this decline in female hormone production, your sensitivity to male hormones such as DHT can increase. If you’re genetically sensitive to DHT, this can affect your hairline and hair thickness.
Menopausal hair loss usually happens between the ages of 50 and 60, with most women prone to hair loss noticing a steady decline in their hair density. It can also occur in your 30s and 40s, depending on the specific age at which you begin to enter menopause. Like other female-pattern hair loss, menopausal hair loss is treatable.