[john Kemp]

john Kemp  asked the Naked Scientists:
   
All of my life I have heart it said that by shaving it makes hair grow back faster, and that once one starts shaving they must continue to for ever more.  Is there any truth to this?  If so what is the science between the rate of growth and shaving one's hair?

John

What do you think?

[exton]

There is no truth to that; shaving or cutting hair does not change the rate at which it grows.

Some people also believe that it causes hair to gro back thicker, but that isn't true either.

[lyner]

I think that it's a story put about by Mums who don't want their little boys to grow up!
I think it could be true, however, that the first hairs (bum fluff) that you get on your chin may be less visible when they are allowed to grow compared with cut-off ones because they taper to a point. Women have a similar problem with their legs.

[Chemistry4me]

I think that it's a story put about by Mums who don't want their little boys to grow up!

Oh jeez, I was fooled by my own mother!

[lyner]

On many other occasions as well, I'm sure.

[Chemistry4me]

She once told me that eating tofu would make my skin whiter. I believed her.

[lyner]

Mine told me that "only common people" eat in the street!!!!!

Hang on - this is general nonsense not General Science!

[wanhafizi]

Yes it does...

That's why it is not advisable for a woman to shave their legs or lips... They will end up with more hairs

[lyner]

Is there actual evidence?

[dionne12]

There is no truth to that; shaving or cutting hair does not change the rate at which it grows.

I believed my frens :)

[Databit]

This is a common myth that has a small teensy bit of truth to it.
When you shave, you are not removing the hair, you are shortening it to skin level.  Compared to growing a new hair, your cut hair has a head start:
1.    It is an active follicle
2.   It already has some hair grown, just you cannot see it below the surface of the skin.
There is also the myth that your hair grows back thicker after being shaved.  There is also a small amount of truth to this as well.  When a hair grows in, it is not a cylinder.  It is in fact an elongated cone.  The tip of a new hair comes to a point and as it grows it gets thicker until it reaches its full thickness.  When you cut the hair off at the skin, you have cut it off at its full thickness.  Now when it starts to grow in, it will be full thickness to begin with.  It will not be any thicker than before, but it will already be at full thickness.  This is also why hair stubble is very stiff when compared to new or longer hair.  The short hair being already at maximum thickness is a lot stiffer.  Fresh hairs are still very thin and bend easily.

[thedoc]

Listen to the answer to this question on our podcast.