No medical evidence supports the claim that detox foot pads take any toxins out of the body. Marketers for these pads claim that putting them on the feet overnight draws toxins out, turning the pads black or dark brown.
An investigative report by the ABC news program 20/20 in 2008 found that the pads do darken overnight, but just dropping water on the pads produced a similar result. Lab analysis of pads from eight volunteers showed none of the industrial toxins that the marketers claim the pads draw. The manufacturer declined to provide any valid scientific studies in response to a request from the ABC reporter.