I had 2 epidural shots in my back at L4/L5 and L5/S1, but my spinal decompression still has a different pinched nerve causing burning in my groin. This seems to take the edge off the burn. I am generally able to feel it working on a few minutes, and it seems to last for a few hours. I’ll take whatever relief I can get! My daughter bought me this for my birthday, but I’ll be buying it again. Interestingly, it worked on her, too. She had 2 titanium bars placed in her chest for pectus reconstruction surgery and she’s had a ton of pain, more than they say she should. She’s medicine resistant, but this surprisingly helped her and she bought her own to put at the sides where the bars are.