Hair. It’s color, texture, and style is just one of the things that makes you, you. But what is hair made of? And how does it grow? Find out below.

Fun Facts

  • Hair strands grow from hair follicles, tiny organs under the skin. Hair can grow on almost every part of the body except the lips, palms, and the bottoms of the feet.
  • Hair is made mostly of the protein keratin. Hair has three layers. The outer layer is the cuticle. The next layer, the cortex, contains the protein. The inner layer is the medulla.
  • Straight hair typically has a round shape. Wavy or curly hair has a more oval shape. Scientists can determine your ethnicity based on the shape of your hair.
  • 95 percent of your body is covered with hair. In fact, humans have the same amount of hair follicles as chimpanzees. It’s just not as thick – or as dark.
  • On average, it takes about seven years to grow hair to the waist and three years to grow hair to the shoulders.
  • Most people have about 100,000 hair follicles on their head. Blondes have the most; red heads have the least. We tend to lose between 50 and 150 hairs every day.
  • Black is the most common hair color in the world. Red is the least common. Scotland has a higher percentage of redheads than anywhere else in the world.
  • Hair is stretchy – and strong. One strand of hair can hold up to 6.5 pounds. A whole head of hair could hold 2 tons.
  • Dandruff is sometimes caused by a fungus. Ick!
  • Hair grows faster in the summer than it does in the winter. During cold weather, blood supply is diverted to internal organs. During the summer, blood flow to the scalp increases, causing hair to grow 10 to 15 percent faster.
  • Eyebrows and eyelashes protect the eyes from dirt, dust, and sweat. Eyebrows are also important for communicating emotions.
  • Forensic scientists can analyze hair to learn a lot about us – what drugs, alcohol, or medicines we’ve taken, for example. Hair is also used in DNA testing.
  • Hair care is big business, but it varies by culture. In ancient Rome, women used pigeon poop to dye their hair blonde. Ugh!! In America, about 80 percent of people wash their hair every day. In Europe, only 25 percent give their hair a daily scrub.

Learn More

Find out how to keep your hair healthy