understanding the science of the hair growth cycle

Understanding The Science of The Hair Growth Cycle

Figuring Out the Mechanism of Hair

If you are anything like me, once you become natural you may expect the rate of your hair growth to increase drastically. I was impatient and annoyed with why my hair still took a long time to grow while others who just went natural had beautiful long hair. What I didn’t realize is that your rate of hair growth happens due to more than just becoming natural. There are so many other factors that affect the growth process. In this article, if you are someone that struggles with understanding your hair growth, you'll get the information behind the science of your hair growth.

How Does Hair Grow?

Hair grows out of tiny pockets in our skin called follicles. Each follicle lives in a cycle of an extended period of growth, followed by a relatively short period of rest. During the resting period the hair is still attached but isn’t growing, we will learn more about that later. After the quiet phase, the hair sheds, and new hair begins to rise to continue the growth cycle.

3 Phases of the Hair Growth Cycle

Anagen (Growing) Stage

The anagen stage is the growth period of a hair follicle. Your hair grows about half an inch a month and sprouts even faster in the summer months than in the winter. The anagen stage lasts about 3 to 5 years.

Catagen (intermediate) Stage

The catagen stage is what is called the intermediate period of hair growth. This phase is a short transition that lasts about ten days. This process is when your hair follicles prepare themselves for the resting phase. During this phase, the deeper portions of your hair follicles start to collapse.

Telogen (resting) Stage

The telogen stage is the resting or shedding period of the hair cycle. This cycle lasts about 3 to 4 months. Once the hair is released, the follicle then stays inactive during the rest of the period and the entire process is repeated. Each hair follicle is independent and goes through the growth cycle at different rates. Otherwise, all of your hair would fall out at the same time.

Explanation of the Hair Growth Process

Your hair begins to grow from a root in the bottom of your follicle. The root is made up of cells of protein. Blood from the blood vessels inside your scalp then feeds into the root which creates more cells and causes your hair to grow. The hair then gets pushed up through the skin as it grows, passing an oil gland along the way. The oil gland helps to keep your hair soft, and it is a natural moisturizer. The hair dies by the time it is long enough to poke through your skin. Just in case you were unaware, all of our hair that we physically see is dead hair. If you are wondering, the hair on the rest of your body goes through this same process, but the entire cycle lasts about a month or so. That’s why body hair does not grow very long when compared to the hair on your head does.

Factors that Affect How your Hair Grows

Now we all know that even with the information given, every person's hair growth journey is different. And why is that? Several factors may be altering how your hair grows. Here are a few things that may be changing your hair growth.


Genetic factors are responsible for the density, length, color, and texture of your hair. That alone is enough information to tell you that everyone's hair grows differently based on factors you cannot control.


As I stated before, hair grows faster in warmer weather. Cold air can make your hair fragile, dry and more brittle which can your growth period.


In general, the incidence of hair loss in both women and men corresponds to chronological age. The older you get, the higher your chances of experiencing hair loss become.

Rest and sleep

Having an adequate amount of rest is essential to your body and hair. Lack of sleep can negatively affect several bodily processes including the growth of hair.


The rate of hair growth also depends on the health of your scalp and follicles. Proper nutrition makes the best possible condition for building thick, healthy hair.


Certain hormones can affect the growth of hair. Among these are thyroid hormone, estrogen, and testosterone. Both hypothyroidism and hyperthyroidism can lead to loss of hair. The female hormone, estrogen, increases the number of follicles in the hair growth cycle as seen in pregnancy. After childbirth, the level of this hormone drops and the hair starts to shed. The male hormone, testosterone, on the other hand, combines with 5AR or 5 alpha reductase to form DHT. DHT is the primary cause of balding in men and women.

Hair and scalp condition

Take the best possible care of your hair and scalp is essential to hair growth. Making sure your hair is moisturized and washed regularly can help your hair grow at a faster rate.

Hair products

Different hair products work better on some than others. I encourage you to experiment and find the products that work best for your hair.

Health issues

Many medical conditions such as thyroid problems, lupus, scalp infections, alopecia areata, etc. can adversely affect the status of your hair in general.


Stress is one of the more common reasons behind sudden hair loss or a stunt in hair growth. When you are under pressure, this puts more follicles in the resting phase of the hair cycle.

Fun Facts about Hair

Here is some extra information about how our hair works that you may not have known.
  • You are born with about 5 million follicles on your scalp which is more than you will ever have.
  • You have about 100,000 follicles on your scalp.
  • Hair grows very fast and grows faster for males than it does for females. The single part of your body that increases quicker than your hair is bone marrow.
  • We lose about 50 to 100 hairs a day. This process happens because the follicles do not all grow at the same time.
  • Some follicles completely stop growing hair the older you become. This process is different for everyone based on genetics.

Hair Growth is Simple!

Although everyone’s hair grows at different rates based on various factors, the process of hair growth is easy to master. It is all up to you. Taking the best care of your hair is essential. As long as you do that, you will see your hair grow no matter how long it takes. In some cases, the way your hair grows isn’t up to you, and it is up to your body. Just remember to be patient during the process!
Back to blog

Leave a comment

Please note, comments need to be approved before they are published.

Featured product