Sort of works
I find that this charcoal teeth whitening powder works only in that it acts as a stronger exfoliator for the teeth and thereby may leave the appearance of "whiter teeth". That being said,  I don't think that it actually whitens the teeth but it does give the appearance immediately after I brush my teeth. I would recommend this as a temporary fix but not a long term one. Giving it 2 stars out of 5 because it works but not well.
Rating: 2 stars