I got these on a whim because they looked interesting. They stuck to my feet pretty well, and even kept them warm overnight (I usually sleep wearing socks but couldn’t when wearing the patches). In the morning, the pads had turned from purple to dark brown/black as the box had described, so I think they worked. I’m going to use them once each month. Note: The pads will leave a sticky residue on the bottoms of your feet when you remove them.