Why is a series of treatments required?
Everyone's hair grows differently, depending
on age, weight, metabolism, hormones, ethnicity, medications
and other factors. But all hair goes through three distinct
growth phases:
Active growth phase (called the anagen
phase), which lasts between 2 and 7 years. During
this phase the dermal papilla actively produces cells which
form the hairshaft. In certain areas of the body, such as
the scalp, the majority (83%) of the hairs are in this phase.
During the anagen phase the hair has an abundance of melanin.
Degradation phase (catagen phase), which lasts between 10 and 20 days, during which the hair
stops growing but is not yet shed. About 3-4% of our body
hair is in this phase at any given time. The hair follicle
shrinks at this time as the hair is prepared for eviction.
Resting phase (telogen phase), which can last for several months, during which the hair falls
out and a new hair begins to form. The hair follicle is not
treatable during this time.
Laser treatment is only effective when the
hair is in the active growth phase. Hairs or hair follicles
in the Degradation or Resting phase need to progress to the
active phase before treatment will be beneficial. Therefore,
multiple treatments are required for long term, permanent
hair reduction.
Also, in a single treatment, not all of the
hair follicles in the active phase will be destroyed. Some
follicles are destroyed, others may be miniaturised into vellus
hairs (light, fine hairs), and some enter prolonged dormancy.
The initial treatment should be repeated to take care of active
hair follicles that were not effectively treated in the first
session as new hair growth is observed, this will typically
be some 2 to 4 weeks later depending on where the treatment
area is. Further treatments should be planned at regular intervals
to clear hairs that are coming out of the resting phase and
into the active growth phase. Given the number of hair follicles
in the resting phase at any given time, this new hair re-growth
can be significant.
Any follicles without a target hair within
will simply grow again and can be treated next time round. |
