After just reading the other review on this product I thought I'd take the time to give my own. I participated in a "study" of this product at my dentist's office six months before it was made available on the mass market. I paid $50, but the price is under $40 now. My teeth are not horribly discolored, just the off-white of very strong teeth. I do not drink coffee, sodas or red wine. We (the dentist and I) were not sure how this product would work given that my teeth were "naturally" a few shades yellower than I'd like and not simply yellowed as a result of surface stains. It takes a month for the full upper and lower course of treatment -- 30 minutes in the morning and 30 minutes at night. I did notice some minor tooth and gum sensitivity, especially initially. Also, the upper strips are a lot easier to keep in place than the lower strips. But, in the end, I was very pleased with the results -- especially at this price. It's been about 9 months since I used this product (results are supposed to last at least 6 months) and I will definitely use this product again when I notice my smile looking less-than-bright.
