Bests & Worsts Reviews from Amazon

I received this product free of charge - thanks to Crest and BzzAgent -to evaluate its effectiveness. I used it twice a day as recommended. One minute for the paste and one minute for the gel each time. I even brushed a little longer and used my electric tooth brush. My teeth were a little sensitive to begin with and this actually made my gums SO sensitive that they would bleed a little each time. I powered through it and sadly, after 4 weeks it still didn't make a difference in the shade of my teeth. Unlike some pictures of the results shown in the reviews, I took the pictures in the same spot of my bathroom and didn't use a filter!!! See for yourself- top is before, bottom is after 4 weeks of use. I'm not happy with this product in the least.