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The
Effects of Shaving
on Hair Growth
Does shaving cause hair
to grow faster, coarser
and darker? This age old
question is still asked
repeatedly. A quick
anatomy lesson on the
structure of the
follicle should help.
The hair follicle and
its hair are
fundamentally one
structure. This
structure can be divided
anatomically into three
segments:
(1) Infundibulum - the
upper, funnel-shaped
indentation that extends
from the polar orifice
in the epidermis (the
little hole where we aim
our needle) to the
entrance of the
sebaceous gland.
(2) Isthmus - the short
midsection of the
follicle, bounded by the
sebaceous gland duct and
the arrector pilli
muscle.
(3) Inferior - extending
from the arrector muscle
to the base of the
follicle.
The expanded lower end
of the follicle is the
hair bulb, which
encloses the oval-shaped
vascular-connective
tissue papilla. This is
an upgrowth of the
dermis containing the
blood supply and nerve
endings to nourish the
follicle.
An anatomic change
occurs at the isthmus.
The entire follicle
beneath the isthmus can
be considered
"temporary" because it
disappears during the
involutional stage, or
stage of regression of
the hair follicle, and
reforms again during the
growth cycle. The upper
segments, isthmus and
infundibular, are
"permanent." At the
isthmus, the cells of
the inner root sheet
disintegrate, and the
outer root sheath -
which is no longer in
contact with an inner
root sheath - begins to
cornify, and form the
hair we aim to remove.
The hair shaft (that is
the hair that is cut off
when shaving) is a dead,
cornified structure that
extends from the
follicle above the
surface of the skin:
only the follicle is
alive. To make any
difference in hair
growth, the follicle
itself must be
disturbed. Shaving or
cutting the dead
structure (hair) will
not have any effect on
the follicle itself.
Shaving hair really is a
form of cutting hair.
Like cutting with
scissors, shaving has no
effect on hair growth.
The myth was exploded by
Dr. Mildred Trotter at
the Washington
University School of
Medicine. Under Dr.
Trotteršs observation,
three girls shaved their
legs from knee to ankle,
twice a week for a
period of eight months.
At the end of this time,
microscopic examination
revealed that there was
absolutely no increase
in the diameter or color
of the hairs before or
after the shaving
period.
Reasons for the
Misbelief After shaving
there is an illusion of
growth, which has given
rise to the false
impression that shaving
really does affect the
growth. Let us examine
those points that appear
to support the idea.
1. The shortness of the
shaft of a shaved hair
allows changes in its
length to be noticed
more easily. If a hair
is shaved right to the
skin and then allowed to
grow 1/16 of an inch, we
readily notice the
difference. However if
the hair was already 6"
long and it grew an
extra 1/16 of an inch
(in the same period as
the shaved hair) no one
would be able to tell
without some accurate
way of measuring.
Taking the example of
the male with a full
beard, it is impossible
to detect the daily
increase in beard
growth. But it is a
different story with the
clean-shaven person and
his "five ošclock
shadow," whose bristle
growth can be seen on
the very same day.
Because the follicles of
terminal hair are not at
right angles to the
skin, shaving exposes
more actual area of hair
to the eye. If scissors
are used to clip a hair,
the cut is usually at a
right angle to the
direction of the growth.
But shaving (given the
angle of hair to blade)
leaves a long-angled cut
at the end of each
remaining hair fiber.
When the hairs grow out
from the skin, they keep
their "thickened"
appearance, especially
as they are being
compared with the white
background of the skin.
2. Apparent coarseness
is caused by the short,
shaved hairs being held
more erect by the
follicles clasped firmly
around them.
Hairs do vary in
structure, length, rate
of growth, and response
to various stimuli. But
the follicle must be
stimulated to cause an
increase in hair growth.
Shaving every day, even
with vigor, would not
affect the deep growing
follicle. The increased
hair growth you notice
after shaving is in all
probability caused by an
increased hormonal
stimulation. Which would
have happened, shaving
or not.
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