How Does My Hair Grow?

The Big "S"

What is Hair?

What is Hair?

 hair science

She blinded me with science...

It always helps to learn about the topic that you love, and you are never too old to touch up on basic science.  Let’s get down to the nitty gritty of what is hair and how is grows.  Hair is actually part of the integumentary system and its real purpose is to regulate your body temperature, and keep foreign creatures (i.e. bugs) out of orifices (that’s why there’s hair in your ears).  But since us naturals rock our hair with pride like a crown, I thought I’d get into what people would have questions about.  FYI, I had to go to my throwback biology books and make sure that I shared the best info for my curlies out there.


                                      Hair is made of a protein called keratin. Keratin is a protein that that is a key structural component in hair and nails.  It is                                       in the shape of an α -helix and contains many disulfide bonds.  Like with any protein, it can be “denatured” by a change                                       in temperature i.e. the heat of a flat iron or blow dryer will straighten the hair.  For more permanent solutions, you can                                         actually break the disulfide bonds (relaxer).


If you look closely you will also see something called the“sebaceous gland”. This gland produces a waxy oily substance called sebum.  This is the natural oil that is produced by your body and releases Vitamin E to your skin.  This is why after several days of not washing your hair it can become oily, and even though sebum is clear and odorless, the bacterial breakdown may produce an odor.


Access amounts of sebum caused by an over active sebaceous glands have been associated with acne.  This is also the reason why keeping hair off of your face can help keep bumps off your face as well--the sebum from your hair deposits on your skin leading to an increase of oil on your face.

Since sebum is produced by a gland, it is controlled by hormones.  In this case, the sebaceous gland is controlled by your androgens, or sex hormones.  Since sex hormones control hair growth it is only logical that you will experience changes in growth and texture based on hormonal changes in your body—i.e. puberty, menstruation, birth control, stress, pregnancy and of course menopause.

Wherever this hair is located on your body, it is growing out from your skin.  The skin is made of 3 basic layers: Epidermis (outer layer that you can actually see), Dermis (middle layer) and subcutaneous layer.  If you look at the picture you will see that clearly it’s not as simple as you may have thought.  Hair follicles are held into the skin throughout the dermal papilla.  There are also capillaries that supply blood to that area of your scalp and any other region the hair is growing.  This is why massaging your scalp is helpful to hair growth—due to the increased blood supply to the hair.


Hair all over your body is constantly growing, falling out and being replaced. Proper nutrition and overall health are major contributing factors affecting hair growth.  Likewise, chemical damage altering the optimal conditions for hair growth will stop hair from growing at its customary rate.  Also, as you get older and all metabolic processes slow down, so will the rate of hair growth.

Here is what the normal hair growth cycle looks like:

Anagen: Permanent hair removal can only occur during this active phase.

Catagen: Hair transitions upwards toward skin pore and dermal papilla begins to separate from follicle.

Return to Anagen:Dermal papilla moves upwards to meet the hair follicle once again and hair matric begins to form a new hair

Telogen: Dermal papilla fully separates from follicle.