What is Hair Made of?

I'll be honest: I never questioned hair until I went to beauty school. It never crossed my mind that hair could be made of something, that it had its own building blocks and structure that came with its own limits. Before beauty school I never knew hair was basically something that needed its own instruction manual, nor did I really care at the time. I did what I wanted when I wanted, and my hair seemingly did what it wanted in return. I was clueless when it came to actually taking control over that mop on my head.

I was one of those girls who used box color for a bit of a change, which meant I was not only changing my locks but also the bathroom sink, bathmat, bath towels, and shower curtain. I always got lucky with my hair (somehow) but I can honestly say it never came out as the true color I was going for. I was also using regular store bought shampoos, like Prell and Herbal Essences. Breck was my number one favorite to keep my hair from being oily, but come to think of it, nothing ever really helped in that area. I also cringe now thinking back to how I would style my hair then- sopping wet hair that I would dry with a straightening iron, watching it steam and hearing it crackle as I ran my hot tool over the strands. My hair was completely fried, and I thought it looked good.

Don't judge me- this is to prove that I've been there. I damaged my hair. The last time I colored at home I used box lightener three times in a row- and as a result had all of my hair hacked off within my third week of beauty school. Sure, the (extremely) short hair was cute- but I had no idea what I had been doing to my hair to reach that point, nor why it felt coarse like 'horse hair'. I was quick to learn, however, and was shocked to find that beauty school was much more complicated than I expected it to be. So, if you're as lost as I was and cant grasp the reality of what that Walgreen's lightener did to your tresses, delve into the (somewhat boring) structure of hair with me:

The Hair Bulb (or 'root')

Hair is basically a combination of nutrients mixed up in the bulb of your hair. The bulb (or root) is hidden within the skin of your scalp and cannot be seen. These nutrients turn to protein and grow out from this bulb as an individual strand made of keratinized (basically hardened) protein. Each individual strand is made up of three sections: the cuticle, the cortex, and the medulla.

The cuticle is the outermost layer of the hair. It is transparent and resembles shingles on a roof. The cuticle really matters when it comes to styling, washing, and coloring. When coloring hair, the cuticle opens so new pigments can reach the inside of the hair strand and change the color. Thinking back to shingles on a roof- imagine if every time the roof of a house got hot, the shingles lifted outward, or opened up. Then imagine if every time it got cold those same shingles laid flat and smooth, shut up tight. This is how the cuticle works. Heat and humidity can make the cuticle open, tangle your hair, and make it frizzy. Using the cool setting on your hair dryer, however, can make the cuticle shut and take the poof out of your 'do. Nice to finally know, right? Also, using store bought shampoos that are full of waxy chemicals can seal the cuticle off, making hair appear shiny and healthy. The reality is that your hair is full of build up and being weighed down. If it seems absolutely impossible to curl your hair, its not your hair- its your hair care.

Healthy Cuticle 

Damaged Cuticle

The cortex of hair is just under the cuticle, and makes up the majority of the hair strand. If the cuticle is your roof, the cortex is the inside of your house. Example: if you have a bad roof and it rains, where does the water go? Straight into your living room. This is the concept of how humidity can effect hair- the cuticle lets it in and the cortex soaks it up. Now imagine me drying my wet hair with a straightener- I was literally burning my own roof off and setting fire to my living room (This is why I don't recommend wet to dry hot tools!). The cortex is also where your hair pigment is held. This pigment is called melanin and this is what is effected when coloring your hair. The original color is removed and the new color is put into place. This would be like buying a new rug for said 'living room', basically swapping one rug for the other. Granted, if you hair has been previously colored, this process can turn more into the tedious job of sanding and re-staining your hardwood floors (more on that later).

Visible Cortex Through Damaged Cuticle 

Finally, medullas are strange little cores that typically reside within the center of the cortex. Some people have this core in their hair and some people do not. In a hair where the medulla is present, it spans from the bulb all the way to the end of the hair shaft.  Its been proven that people with thinner hair do not typically have medullas, while thicker strands normally do. From most standpoints, there is really no known reason to have one, although some science suggests that this is where DNA is stored. All I can say about the medulla is that some people have basements while others don't.

And Here is Your Lovely Medulla (if you have one)

After structure, the rest is chemistry. Each strand of hair (keratinized protein) is made up of amino acids that are held together by polypeptide chains.

Polypeptides in Hair

Polypeptide chains are held together by side bonds. Bonds are important to you because their integrity determines the integrity of your hair. Key bonds are altered when it comes to washing, drying, styling, and chemical processes. Chemicals effect the hair because most fall into harsher ends on the pH scale. Changing the pH of these bonds can make them break down significantly, thus explaining the 'horse hair' effect I received from box lightener. 

Common Examples on pH Scale

Where Hair Lives on pH Scale

As you can see, hair is much more complex than most of us give it credit for. It has its own structure, reactions, and chemical make up. For a nonliving organism, its pretty impressive. I haven't used a box color or dried my hair with a straightening iron (cringe) since I started beauty school- after learning the overall build of hair, I feel it deserves more respect than that.