• Question: How does hair grow?

    Asked by v1997 to Asif, Laura, Lena, Sean, Viv on 19 Mar 2012.
    • Photo: Lena Ciric

      Lena Ciric answered on 19 Mar 2012:

      Hair grows out of hair follicles that are found in your skin. Hair is mostly made up of keratin (a protein) and is coloured by melanin (the same substance that is in our skin and makes us tan). Stem cells in the follicles are generally responsible for the actual production of the hair.

    • Photo: Sean Murphy

      Sean Murphy answered on 19 Mar 2012:

      Everyone’s hair grows differently, depending on age, weight, metabolism, hormones, ethnicity, medications, and other factors. But all hair goes through three distinct growth phases:

      1) Active growth phase (called the anagen phase), which lasts up to several years. At any given time, the majority (85%) of our body hair is in this phase. During anagen, the hair has an abundance of melanin.

      2) Regressive phase (catagen phase), which lasts about two weeks, during which the hair stops growing but is not yet shed. About 3 – 4% of our body hair is in this phase at any given time.

      3) Resting phase (telogen phase), which lasts 5 – 6 weeks, at the end of which the hair falls out and a new hair begins to form. Approximately 10-13% of our body hair is in this phase at any one time.

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