I tried everything, whitening toothpaste, strips, trays and nothing. I tried snow and I noticed a change first day... stuck with it and wholly moly what a difference. The best compliment is when someone says I love your smile. You know it’s because your teeth are white. Since snow I get compliments all the time. I used it for three weeks and now just once a month to maintain. Absolutely the best product. After about six months I had an issue with the light and they immediately replaced it no questions asked. Running perfect ever since. Love this product, would absolutely buy again, but not necessary five year warranty.... who does that. You must really believe in your product. Don’t wait..... this is absolutely the best product I have tried.