how do laser treatments for fine hair fail?

Hair Removal Methods Laser hair removal
1

It is often said that laser won’t work on fine hair. When it fails, exactly how does it fail? That is, which of the following 2 possibilities is true:

  1. There is shedding, but everything grows back.
  2. There is no shedding in the first place.

I can see why #2 would happen for thin hair. But even if there was complete shedding, is hair still more likely to regrow if it is fine than if its coarse?

2

Coarse hair = more pigment = more energy absorbed and delivered to follicle = follicle more likely to be destroyed

Fine hair = less pigment = less energy absorbed and delivered to follice = follicle less likely to be destroyed.

3

I see. So if you have fine hair, the follicle may absorb enough energy to be damaged to the point that the hair falls out, but not enough for the follicle to be destroyed, right?

4

Right