Now I remember why I quit using my Zapper 2 years ago when I first bought it: I have neuropathy and it causes me allot of pain for a several days after using it. I have pain and burning sensations under my skin. I guess my nerves cannot handle the electrical stimulation. Also, I developed a small Herpes sore on my lip which is unusual.
However, I do believe that using the Zapper has resulted in germ death (specifically Lyme infection) because I am experiencing several classic Herzheimer symptoms. So, that is encouraging. You have to feel worse before feeling better!