1, black or other colored liquid will be discharged during the use of the foot patch, which is usually a physical phenomenon.
2. It is mainly due to the reaction between sweat on the soles of feet and foot powder. Similar to oily products in cosmetics, powder is not easy to absorb, but oil is easy to absorb.
3. The main reason why the foot patch does not change color or drain oil after use is that it is not firmly attached or there is no sweat on the soles of the feet. It is recommended to stick it firmly after soaking in hot water.