Hair grows out of pilous follicles located on the surface of the skin. It starts to develop in the early phases of fetal life, and falls into a regular cycle throughout our entire life. In human beings, the hair cycle in is not synchronized.

Normally, the majority of hair on the scalp is in the growth phase, with fewer individual hairs in the transition and rest phases of the cycle. The growth phase of the pilous follicles on the scalp is longer than the other phases, and this time difference helps determine the final length of hair.

Hair is affected by what goes on elsewhere in our body, especially by hormones, fatigue, and stress. These influences impact the “hair factory”, that is, the dermal papilla located at the hair root. This papilla forms the follicle, and is rich in cells; and more importantly, it is home to numerous capillaries, whose activity and overall number are essential.

The desire of many men to combat hair loss has pushed them to try each and all possible (and some impossible) solutions; which has opened the door to every kind of scam. However, somewhere between total resignation (“there’s nothing you can do, anyway”) and the misleading promises of each new “miracle” lotion brought to market, there are sensible alternatives for treating hair loss.

Chemical Composition of Hair

The basic composition of hair can be broken down as follows:   28% proteins 2% lipids The remaining 70% are mineral salts and amino acids

As previously mentioned, hair is formed from keratin, thus this is the most abundant protein in hair. We can find two types of keratin in our body:

	Soft: found throughout the skin as scales.
	Hard: forms nails and hair, and has a uniform, compact mass, which gives it its greater hardness.

The chemical composition of hair is the following:

	44% carbon
	30% Oxygen
	15% Nitrogen
	6% Hydrogen
	5% Sulfur

Different types of Hair

Your hair is strong and shiny, but it does not allow curls. This type of hair tends to be more oily than dry. The advantage of straight hair is that the cuticle contains several layers, making it very resistant to damage. You would have to subject your hair to excessive perms and dyes to make it have a damaged appearance.

There are three types of straight hair:

	Fine and thin: Soft and Shiny
	Medium Thickness: Lots of body; you can do most everything you wish with this hair
	Thick: The most resistant to curls

This type of hair tends to be thick. You can see the “S” form in your hair. This kind of hair clings to your head, even if you cut it in layers.

There are three types of curly hair:

	Fine and Thin: Can be curled or straightened easily
	Medium Thickness : Tends to “hug” your head. It is easy for it to frizz
	Thick: Hardest to style, it frizzes easily

When we say curly hair, we imagine a thick hair; but actually, curly hair is very fine and soft. Curly hair does not have a flat surface, and its cuticle is not smooth, so it is difficult for it shine. It looks straight when wet, but as soon as it starts to dry, it gets curly again. Humidity causes it to frizz.

If you have healthy curly hair, it will be shiny and soft, with smooth curls. Damaged curly hair looks dull, dry, with poorly defined curls.

Coiled curly hair is wiry, tightly curled, and very fragile. This type of hair does not shine, but it feels silky. Although it looks strong, if you have this type of hair you already know that is actually very fragile. It is the kind of hair with the fewest cuticle layers. It is difficult to grow this type of hair long, precisely because is very fragile. It tends to break every time you brush it. However, if you always wear it in braids, and avoid brushing it, you can get it to grow longer.

There are two types of coiled curly hair:

Scalp

It is made up of two, structurally-different layers: the epidermis, a protective layer; and the inner dermis, which maintains/nourishes the epidermis and hair thanks to the large number of blood vessels it contains.

At the level of the hair root (called a pilous follicle), it has developed a “trade zone” (called the dermal papilla) where hair can get its vital energy.

The sebaceous gland, located toward the top of the hair canal, secretes an oil that is essential for lubricating the entire surface of the hair, making it waterproof, and protecting it from external agents, fungus in particular, to ensure its protection.

Hair Layers

The visible part of the hair is called the “shaft”, and it is made up of 3 layers:

	The Outer Layer: Also known as cuticle: made up of protecting, overlapping scales
	The Miiddle Layer : Also known as cortex: made up of agglomerated keratin fibers. Pigments responsible for hair´s natural color are found at this level
	The Inner Layer : Also known as medulla