Stages of Hair Growth


When we consider skin is an organ of the body, its metabolic functions may not come to mind including producing and synthesizing vitamins with the sun’s rays and its structural differences. For example, face skin heals much better than shoulder skin does. An entire medical specialty, dermatology, focuses on skin’s characteristics and its related parts including hair and nails.  

In this post I’ll address the three stages of hair growth. Why? Because, quite honestly, we fear losing it. If we understand its stages of growth, we can better comprehend the medical treatment’s recovery process. 

Shedding hair?

Everyone’s heard the expression “My cat (or my dog) is shedding” with reference to loose hair we find on clothes, cushions or flooring surfaces. 

Shedding is in fact a characteristic of mammals but unlike animals, we humans don’t depend on our hair to stay warm. We see actor Hugh Jackman as Wolverine with a steady amount of hair in each successive film yet his hairline may be diminishing every year. 

Hair Growth Stage by Stage

To understand “The Greatest Showman’s” predicament as well as everyone else’s let’s now consider hair’s growth cycle.


Anagen, the First Stage 

The initial hair growth stage is our favorite, since it brings with it long colorful hair, requires a regular haircut and varies in duration on different parts of the body. On the head it can last between 2 and 6 years and produce thick rich hair. But on the arms and legs it may last only a few months, so underarm braids are only possible in jest or by exception.

The Anagen stage determines the rate and amount of your hair growth. For example, your chin is where your hair grows the quickest at .38 cm a day, from increased cell reproduction and where changes from toxins, medicines or hormones are most visible. 

Hair color comes in during the Anagen stage. Interestingly enough, melanocytes which produce the pigment melanin stop functioning at some point. The resulting gray hair is different in composition and less manageable than the original color and it grows more quickly as is evident in beards and mustaches. 

Catagen, the Second Stage 

In this shortest stage, on the head it lasts for 2 or 3 weeks. The hair stems detach from the blood vessels, the cells die from undernourishment in a process called apoptosis, and abundant keratin is produced which then surrounds the new hair-bearing follicles hidden beneath the skin’s surface in the form of a club.   

Telogen – Exogen – Ketogen, the Third Stage 

The third stage can be divided into three stages for the sake of clarity. 

After the growth in the Anagen and Catagen stages the hair enters into the Telogen stage when it naturally falls out. First, a follicle’s length is reduced by 50% as seen in Figure 1. Then the Exogen stage begins when proteolytic enzymes which break up proteins now join together. One hundred hairs a day over the whole body may be lost, but others are soon to sprout. So don’t worry if you’re losing some hair every day. The empty hair area enters into the Ketogen stage for the time it takes for a new hair-bearing follicle to appear on the surface again during the Anagen stage.  

The Telogen or replacement stage is triggered from between the 1st and the 3th month after having a hair transplant procedure. You may think you’re losing hair from your procedure but new healthy hair is growing just beneath it. In a word, the former hair falls out not the new hair that will grow in its place. In time you’ll have beautiful new hair. When patients are surprised by their hair loss, we tell them to relax because in about 100 days, the time it takes for hair growth to become visible again, their new hair will shoot up to the surface. 

If you want to find out more about hair’s growth cycle, or if you have any specific questions you’d like us to clarify in this blog, feel free to leave us your comments below. 

You may also be interested 


Leave a Reply

Your email address will not be published. Required fields are marked *