I've tried other detox foot patch brands and the Dtox Foot Patch which is very expensive! They offer a variety of foot patches to cleanse certain organs, like the patch that's specifically formulated to cleanse the kidneys, liver, etc. I tried a variety of Dtox Foot Patches and honestly felt no effect. I was caught up in the foot detox craze thinking this was my answer to my problems, or so the ads claimed it would answer my problems. First off, there's no scientific science behind these patches. It's a form of Ancient Asian cultural medicine where they believe in Reflexology which is the belief that zones in the feet correspond to each organ system. I thought it was worth a shot and spent a great deal of money on these Dtox Foot Patches and think it's a total shame! Yes, after wearing them on my feet overnight, the patch did turn black and smell bad. I thought at the time, wow I'm being detoxed! But after doing this nightly ritual over and over I physically never felt any changes in my body. So I wanted to know why these patches were stinking and turning brown after wearing them on my feet, and I have my own thoughts behind this. When you place a patch on the bottom of the foot overnight, it's recommend to wear socks, the feet sweat, at least mine did. These patches contain ingredients like wood vinegar which is dried and ground up with tourmaline a stone or mineral, bamboo vinegar, and a variety of herbs, so when the sweat is mixed with these ingredients the color change happens and the smell of the herbs and vinegar comes out, which gives the illusion of the body being cleansed through the feet. I mean I seriously bought into this idea and it may work but not by the DTox company, these pads are a expensive gimmick! Not to say there's no truth behind detoxing through Reflexology but I'll contact a medical professional about this instead of wasting more money on these useless foot pads!