Androgenetic alopecia (male-pattern baldness)
Androgenetic alopecia (male-pattern baldness) affects about 80 million people in the US. Studies About 62.5% of men and 37.5% of women will suffer from it. Male balding is believed to be a result of sex hormones or androgens, particularly dihydrotestosterone (DHT). DHT can also contribute to female hair loss.
So, what is the connection between DHT and male hair loss? About 50% of men, in their 50s, experience balding as a result of this hormone. A 1998 study showed that hair plucked from balding people had higher levels of DHT than those from non-balding people.
What is dihydrotestosterone? DHT is an androgen that gives men the male uniqueness during puberty. These characteristics include body hair, a deeper voice, growth of scrotum and penis, sperm production, etc. Enzyme 5-alpha reductase acts as a catalyst in the formation of DHT from testosterone.
Hair typically grows from hair follicles throughout your body. At the end of each growth cycle, these hair follicles regenerate new strands of hair to replace the old ones. High levels of DHT are harmful to this cycle.
Androgens, including DHT, are responsible for hair growth in armpits, beard, and pubic areas. However, the hair on your scalp does not require DHT to grow. Presently, there is no solid explanation for why DHT enhances growth in other areas except the head.
When the excess DHT travels in the bloodstream to your scalp, it can shrink your follicles through an unknown process. It causes your hair to grow out, looking thin and fragile. It will also shorten your growth cycle, which usually lasts between 2-6 years. Your hair regeneration phase may also become longer after shedding the older hair.
Some people become more vulnerable to DHT effects on their hair because of variations in their androgen receptor (AR) genes. These are proteins that join with testosterone and DHT. This binding activity ensures a normal hormonal progression, such as hair growth.
Differences in androgen receptors can allow androgen receptivity. If this occurs in your scalp, the chance of male-pattern hair loss increases.