Activated charcoal is a finely milled black powder made from coconut shells. The charcoal is processed with high heat, which “activates” it. This changes its internal structure, making it more porous than regular charcoal. It’s also processed in this way to rid it of any additional substances that are harmful to humans.
Always make sure the products you use aren’t too abrasive for your teeth. Relative Dentin Abrasivity (RDA) is a guide to measure abrasiveness for dental products and it is recommended you use products of a score of 200 or below. Activated charcoal powder scores about a 70 to 90 on the RDA scale while most whitening toothpastes score between 100 to 200 RDA.