Your hair, like your skin, is often subject to the harsh elements of the outside world. UV rays, chemicals, dirt, and other toxins can work a number on your hair. It is also exposed to harmful chemicals like sulfates, parabens and synthetic fragrances that most other shampoos and conditioners contain.
Your scalp plays a key role in hair health as well, and, unfortunately, the scalp is subject to the same effects and chemicals as the rest of your skin, which is why it is important to take excellent care of your hair and scalp to avoid uncomfortable conditions like dry scalp, dandruff, oily hair, and even hair loss.
We believe that it is important for you to have a basic understanding of how the hair and scalp works so that you can properly assess the state and condition of your hair, and so that you understand what is happening when you put a cleansing or management product like a shampoo or conditioner in your hair.
So, to begin, the scalp is composed of the same three layers as the rest of the skin (see "Skin Health"), the "epidermis", the "dermis" and the "hypodermis".
The dermis layer is where the hair follicle resides, along with the oil-excreting sebaceous gland which waterproofs the hair and skin. The hair follicle is where the hair, a "protein filament" (a chain of proteins), grows from in four cycles.
The first cycle is called the "anagen" phase, which is the active hair growth period. During this period, hair grows about half an inch every 28 days. This phase lasts anywhere from 2 - 6 years.
The fourth and final cycle is called the "exogen" phase. In this final phase, the hair shaft is released from the hair follicle and shed from the body. This coincides with the "early anagen" phase, which is simply the beginning of the next cycle.
These four cycles are all going on separately for each follicle. So while one follicle might be in the telogen phase, another may be in the anagen phase. This is why most people's hair doesn't all just fall out temporarily during the exogen phase.
With this knowledge, we hope that it is clear that a healthy, well taken care of scalp dermis layer directly affects the health of the hair that grows from it. A scalp that is nourished with vitamins, minerals, and a proper pH balance will produce healthier, fuller hair, and will make sure the four phases of hair growth continue to be a cycle, instead of the cycle simply ending on the exogen phase, resulting in mass hair loss.