Page 91 - Chapter 3 - Laser/IPL Hair Removal

Chapter 3 – Fundamentals of Laser/IPL Hair Removal 2nd Edition
Hair treatment intervals – what is the ‘best’ time to leave between sessions?
The follicle germ/stem cells promote anagen hair growth at consistently regular intervals resulting in periods of active growth, followed by inactivity. The duration of these periods depends on the which part of the body is being considered.
Using the model we created above, we wanted to determine the ‘best’ intervals between laser/IPL treatment sessions to generate the best outcomes. Our main criterium was that we wanted to retreat areas when the maximum number of follicles were back in anagen.
Interval No. of sessions at 60% efficiency
(weeks) Upper Lip Chin Bikini Legs Pits
477797 676686 866676
Table 20 - Number of sessions required to kill almost all follicles across the body at an efficiency of 60% (which is fairly typical).
In the real world, nobody can deliver a 100% efficient treatment. So, we can never kill every anagen follicle when we treat. The most realistically achievable efficiency is somewhere between 60 and 80%, in most cases – but many do not appear to achieve this level of efficiency, for various reasons. In Table 20 we show the number of sessions required to kill virtually all follicles across the body when assuming a 60% efficiency. These numbers are very close to what many clinics around the world achieve.
Table 20 suggests a surprising increase in the number of required sessions for a relatively small drop in EKR between 60% and 40% - more than double. Figure 45 shows number of required sessions for a number of body areas, assuming 8 week intervals between sessions.
Figure 45 - The number of treatments required to kill all follicles for a number of body areas, assuming an 8 week interval in each case. This clearly shows that adopting such an approach results in many more repeat sessions than may be necessary.
________________________________________________________________________ 91 Chapter 3, Ed. 2.0 Laser/IPL Hair Removal
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