Activated charcoal is a black powder made from coconut shells, bamboo, or other organic materials. It has been used for centuries to treat poisoning and diarrhea. In recent years, activated charcoal has become popular as a natural remedy for a variety of health conditions, including teeth whitening and bad breath.
There is some evidence to suggest that activated charcoal may be effective for teeth whitening. Activated charcoal is highly absorbent, and it may be able to remove stains from teeth. However, there is no scientific evidence to support the use of activated charcoal for bad breath.