The product is as advertised. I have been following instructions for application of the powder. However, after around one week of brushing for two minutes a day I felt that it may be more effective through doubling the time to four minutes. My teeth appear to be a little more shiny, but a tea stain across my lower front ones is proving stubborn for removal. Having said that, there are signs that it is fading now a little. My dentist tells me that my teeth have yellowed naturally through age, and this is something which I hope that the product will address over time.