• Question: why does hair grow back when we cut or shave it?

    Asked by krazykatie to Chris, Josh, Rebecca, Rob, Susan on 17 Jun 2015.
    • Photo: Susan Cartwright

      Susan Cartwright answered on 17 Jun 2015:

      Because hair grows from the bottom, not the top. New hair is created in the follicle, which is like a little pit in the skin. When you cut the top off, new hair is still being produced, so the strand will continue to get longer.

      It is possible to kill follicles, e.g. by passing an electric current through them. Then the hair does not grow back. Some women with strong facial hair growth have this done because they find the facial hair embarrassing, but it is a tedious and expensive process.

    • Photo: Rebecca Dewey

      Rebecca Dewey answered on 18 Jun 2015:

      Hair continually grows; the end of it that is in the skin, the follicle, is continually producing new hair. If you were to never cut it, it would carry on growing at roughly the same rate, but the unattached end would gradually get fragile and break off every now and then. That’s why certain hairs seem to stay the same length all the time (like the hairs on your arms). Other hair is naturally predisposed to reach a longer length, such as the hair on your head, or men’s facial hair and therefore we cut it to keep it the length we want it. But the follicle doesn’t know or care whether we’ve cut it or not, it just keeps growing new hair regardless!

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