How Does Men’s Scalp Hair Grow?

If you are a man experiencing thinning hair or hair loss, understanding the biological mechanics that drive hair growth is important for understanding why you may be experiencing a slow down and what you can do about.

As a man, you start out your life with about 100,000 hair follicles that produce hair on the top, back, and sides of your head.  Follicles are grouped in follicular units, with each unit containing one or clusters of up to four follicles.  Follicular units are an important term to remember if you are considering a surgical hair transplant procedure.

Hair begins its growth from the bottom of the follicle, at the root, where protein rich cells divide over and over, building the hair strand.  As with every other part of our bodies, blood vessels carry the fuel necessary to energize follicle roots to grow hair.  This cell division and strand building pushes the hair up, through an oil gland, and then through the scalp’s surface.

In a normal healthy scalp, about 90% of all follicles will be growing hair. You can expect about six inches of hair growth a year, but remember, this will also depend on other factors, such as your general health, diet, and stress.  While oil glands give each hair a protective coating, making your hair shiny, the hair itself is dead once it reaches your scalp’s surface.

This growth period, called the Anagen phase, usually lasts about three years, but for the lucky few, their hair can keep growing for up to six years.  The Catagen phase is when the root stops producing and the actual hair end, called club hair, is shifted slightly up, but not out of the hair shaft.  These changes take about two to three weeks.

The follicle and root rest for about 100 days in what is referred to as the Telogen phase.  At the end of this resting period, the follicle enters the Exogen stage and sheds the hair.  It is normal to shed up to 100 hairs a day, and is essential for making way for new hair growth, or a follicle’s Anagen phase.

Because of the male hormone testosterone, men’s hair grows faster than women’s.  Unfortunately, that very same hormone which gives us our male attributes is the pre curser to DHT (Dihyro Testosterone) which causes some of us to experience androgenic alopecia, or male pattern baldness.