Well, so much for the block helping for pain...started having the burning on fire pain again yesterday afternoon. So the block worked for approx. 1 and a half days. But I gotta say, that day and a half was fantastic! (right foot only). I need to ask, do these blocks build up in your system?? Meaning, after block #4 in 4 weeks from now will it have a better effect for longer because I have had so many of them?? Karen