OK!
This is really quite simple!
Human thermal/pain receptors (nociceptors) are triggered at around 45 C. Below that temperature you feel heat – above it, and you feel pain. NASA has proved this beyond doubt!
So, to achieve permanent, or even ‘semi-permanent’ hair removal you need to apply sufficient heat energy, for a sufficiently long time, to fully denature the germ cell proteins.
It’s not rocket science – I know this because I did a course in ‘rocket science’ as part of my original degree!!
The upshot is, if you want to permanently destroy hair follicles using heat energy (supplied by either light or radio frequency or sorcery) then you need to achieve a suitably high temperature for its corresponding time.
That temperature NEEDS to be above 45 C.
Do you see where I’m going with this….?
If you don’t feel thermal pain, you will not destroy the follicle stem cells.
Simples!
Mike.