My hair is mostly dark brown. (There are some reddish and blonde hairs on my face, but from the context I don't think that's relevant.)

I suspect the trouble with the lidocaine has to do with how superficial the application is - the numbing works on the epidermal layer, but the follicles in the deeper dermis layer aren't getting numbed. I think applying higher concentrations for longer before the appt. seemed to help, and maybe that's because it is absorbing deeper into the dermis?

I also felt the lidocaine worked better on the genitals than my face, and I keep wondering if it had to do with how many nicks there were down there. When I shave my face, I don't usually cut myself or bleed at all. The skin of my mons pubis has a tendency to be like gooseflesh and the razor cuts little bits of the skin to get at the hair, so I was bleeding a lot. This might have resulted in more of the lidocaine getting absorbed. However, this feels rather speculative and it could just be that there is less density of hair and fewer nerves than on the face. (There is also something about the psychology of having the light, the feeling of the blast of the laser, and the noise all on your face - it is much more intense and maybe that changes the perception of the pain.)

I'll have to continue to experiment and see if I can shave in a way that doesn't cause cuts, and see if the same lidocaine is as effective.

Trying the 23% on my face will also give some important feedback.