These are the first time I am using them. I wanted to try these for the longest time and wanted to see if they worked. The first night I used them, I was not really sure about it but I kept going. By the third night, I started to feel a difference between them. I felt more refreshed and the pain in my lower back was minimal. I was feeling better in the mornings and work up early at times, FYI, I am not a morning person. I am most likely going to buy another set of these soon since I am down to my last package. The black stuff is still there, so that must mean I still have toxins left in my body. These were easy to apply, but make sure not to take them off until the next morning. If you do, they will not stick back together much. Make sure to wash your feet before putting these on. Sorry to show you my gross feet.