I have just started the b12 and am hoping for some sign that it works. the site that I mentioned is http://www.tenspros.com and they sell ultrasound devices, tens devices and lots of medical equipment at really good prices. I paid a lot more for mine because I didn't know about this site. The cold laser therapy device is too pricey here, though. I bought mine on Amazon. I am really serious about getting rid of this terrible pain and lack of sleep because of it.