How Does Hair Dye Work?

Back in the old days, when hair dyeing was in itsthe natural colouring of your hair but doesn't lighten it
infancy, hair color products routinely gave off a ratherdue to the fact that it contains no ammonia or
noxious rotten egg type of odour. It is good news thenperoxide.
that today, the modern equivalents of these bygoneDemi-permanent hair dye colours usually last a lot
products smell a whole lot nicer. The great thing aboutlonger than the semi-permanent variety, at around
these present versions is that they are so much22-28 shampoos. The pre-coloured molecules enter
simpler to apply as well. Whether it be to wet hair orthe hair through the cuticle, as in the semi-permanent
dry, quite a few of the colouring products availabledye but once in the hairs cortex they fuse with other
today can be worked into the hair forming a shampoomolecules to give medium sized colour molecules.
like lather, left to work its magic (with or without aBecause these molecules are larger in size, they now
plastic hair covering piece, depending on the product)take that much longer to wash out of the hair.
then rinsed out and conditioned. How simple is that?Demi-permanent hair dye does not contain any
Unfortunately, simplicity comes at a price, as is mostammonia so the natural pigmentation of the hair cannot
often the case in life. Chemicals present in the hair dye,be lightened, but it does contain a small amount of
such as ammonia and peroxide, can be just as harshperoxide which allows for slight (but noticeable) colour
and damaging to your hair today as were thechange.
chemicals in the early days of hair colouring, and this isPermanent hair dye is what is used for major hair
especially true if you dye your hair too often. Obviouslycolour changes, for example going from black to
your hair is going to react differently to different levelsblonde or vice-versa. Permanent hair dye uses both
of the chemicals found in various types of products,peroxide and ammonia so when the molecules enter
but generally there are three main types of hairthe hair they react and expand to a size that cannot
colouring levels used by the main hair productactually be washed out. The only way out with this
companies today- semi-permanent, demi-permanentmethod, apart from re-dyeing, is to let the hair grow
and permanent.out. This type of hair dye reacts by lightening your
Semi-permanent colour basically adds colour to thenatural hair pigmentation, forming a new base and then
hair without changing the natural colouring too much.adding a new permanent colour which combines with
This kind of hair dye consists of tiny molecules thatyour own natural hair pigment. This is the reason the
enter the hair through the cuticle but do not affect thecolour you have to chosen to dye your hair with may
hairs natural pigmentation. After several washes theselook different on you than on someone else who has
molecules, because they are so small, eventually exitused the same colour. As hair grows at a rate of
the hair shaft leaving your hair as it was before theabout half an inch a month, this kind of hair dye will
hair dyeing treatment. Semi-permanent hair dye usuallypresent the problem of roots, so you will probably
lasts from six to twelve shampoos and has the abilityneed to touch up the dye every few weeks.
to cover up to fifty percent of your greys. It enhances