Here's an article about laser hair removal:
How does laser hair removal work?
Laser hair removal is the use of laser energy to produce long-term hair
reduction. This is accomplished by producing heat in the hair, which is
transferred to the hair follicle, which in-turn produces inflammation,
and this inflammation sends a signal to the hair follicle to go into the
resting (telogen) phase.
What is a laser, really?
First of all, what is a laser? A laser is a device that produces light
of a single color or wavelength. In dermatology, these lasers produce
pulses of high-energy light that is taken up by the desired target. In
the case of hair removal, the target is the melanin pigment contained
within the hair shaft.
A delicate balance
The tricky part of laser hair removal is targeting the hair shaft without
damaging the melanin pigment in the surface of the skin. Thus the laser
light has to be on long enough to heat the hair, but not too long to allow
that heat to spread to the surrounding skin causing damage. In addition,
the darker a patient's skin, the more difficult it is to avoid injuring
the surface of the skin while treating the hair. For this reason, there
are three main types of hair removal lasers that are used today, and depending
on the thickness of the hair and the color of the skin, one laser may
provide benefits as compared to another.
When Performing Laser Hair Removal, Experience Matters
In addition to lasers, intense pulsed light sources are also used for
hair removal. These light sources do not emit a single color or wavelength
of light, but emit light containing many colors. It may be more difficult
to predict the outcome and avoid complications when using light sources
that contain many wavelengths of light. However, the results with any
device depend upon the experience of the practitioner.
How many treatments?
Normally, a series of three to five treatments are administered at four
to eight week intervals depending upon the location of the hair. Following
the initial series of treatments, subsequent treatments are administered,
usually at longer and longer intervals. Some number of maintenance of
treatments may be needed to keep all the hair away in a given area. After
a single treatment, the hair in a given area is usually reduced in amount
and thickness for a very long period of time. However, it may not be completely
gone. To keep an area completely devoid of hair, maintenance treatments
are always required. These maintenance treatments may eventually be required
at only yearly intervals or even longer. This depends on the area being
treated as well as the individual. As with any other traits in an individual,
the frequency of maintenance treatments varies considerably from person
to person.
