You may have seen toothpastes and whitening treatments touting the ability of activated charcoal to absorb stains on teeth. There is limited scientific evidence to support its effectiveness and safety for this purpose. Some people report seeing temporary improvements in tooth color after using activated charcoal. However, it can potentially damage tooth enamel and gums due to its abrasive nature. Plus, long-term use of activated charcoal for teeth whitening may lead to unwanted side effects. These could include tooth sensitivity and gum irritation.