Hair Science 101: What Is Hair Made Of?

by Viviscal Hair Expert on May 17th, 2018

Are you curious what hair is made of? Although hair grows in a countless variety of colors and textures, at a cellular level all human hair is essentially the same. And in order to grow the healthy hair you want, you have to start by understanding what your hair strands are made of. Keep reading to learn more about the building blocks of hair and what helps hair to grow.

Understanding What Hair Is Made Of

Hair is mostly made up of a hard protein called keratin. Keratin is also found in fingernails, toenails, and skin. Hair keratin is formed by amino acid molecules linked by a cysteine disulfide bridge. These amino acids come from the protein in our diet, which is why it’s important to eat enough protein to support healthy hair growth.

A single hair is made up of the hair follicle and the hair shaft. The hair follicle is the part of the hair beneath the skin, and is where new hair growth actually occurs. The base of the hair follicle, called the bulb, contains stem cells that produce the hair shaft. The bulb receives nutrients necessary for hair growth via a tight grid of blood vessels within the scalp. The hair follicle also includes a sebaceous gland, which produces sebum (or oil), which keeps the hair and scalp moisturized.


Anatomy of the hair beneath the skin

The hair shaft is the part of the hair that extends outside of the skin and is made up of the following parts:

  • Medulla – A honeycomb-like core of glycogen (a sugar) and citrulline (an amino acid)
  • Cortex – A hard keratin layer surrounding the medulla
  • Cuticle – An outer protective layer that gives hair its shine

The cortex and the cuticle also contain a pigment called melanin, which determines your natural hair color.


Cross-section: 3 parts of the hair strand

The Building Blocks of Hair

However, hair requires more than just protein to help it grow. These vital nutrients also help hair to grow long and strong:


Biotin is a water-soluble form of vitamin B, also known as vitamin B7 or sometimes “vitamin H”. Biotin supports hair growth by metabolizing amino acids from foods. Amino acids make up the building blocks of protein, and thus help to form the keratin in hair. Biotin also helps to improve the strength and resiliency of the cortex to defend hair from environmental damage.


Iron is necessary for hair growth because it helps to form red blood cells. Red blood cells deliver oxygen and nutrients to the hair follicles, supplying them with the necessary materials to support hair growth. Hair loss is often a symptom of iron deficiency anemia.

Vitamin C

Vitamin C helps the body to absorb iron, thus making sure the body has adequate red blood cells to support hair growth. Vitamin C is also a powerful antioxidant, and protects hair follicles from damaging free radicals that contribute to discoloration and even hair loss.


Zinc supports DNA production, which is required for the division of all cells, including hair follicle cells, and thus, is important for hair growth. Zinc also helps to balance hormones, which is beneficial because unbalanced hormones can be a major factor in some types of hair loss, especially in women. Without enough zinc, the protein structure of the hair follicle can deteriorate, causing hair shedding.


Niacin is another B vitamin that is necessary for healthy hair growth. Niacin (vitamin B3) helps to repair the DNA in hair follicle cells. DNA tells all cells, including those in the hair follicles, how to behave, so without enough niacin, follicles may not produce hair efficiently.

Colorful-pills-supplements-vitaminsWhat Helps Hair Grow?

The best way to help hair grow is to make sure that you’re consuming all the vitamins and minerals necessary for healthy hair growth. A diet rich in protein, biotin, iron, vitamin C, zinc, and niacin will fuel hair follicles to optimize their ability to grow hair.

Add hair-healthy foods to your diet including eggs, spinach, beans, citrus fruits, kale, peppers, chicken, oysters, beef, asparagus, mushrooms, and fish.

One of the easiest ways to incorporate these key nutrients into your diet is simply by taking Viviscal hair supplement. Viviscal is formulated with biotin, iron, zinc, vitamin C, and niacin to help your hair follicles grow thicker, stronger hair. Taking just one Viviscal tablet twice a day is clinically proven to support existing hair growth, growing thicker, fuller hair within three to six months.*