Teeth Whitening Gel : Not a Drastic Difference

I received this product for free for testing and reviewing purposes, and did so for several consecutive days until the sample ran out. The tube said it was a weeks worth of product, but I got a few more days out of it than that. I tried the product with the Go Smile "luxury" tooth paste on a dry toothbrush day and night, and I did not notice a drastic difference. The product tastes similar to typical whitening strips (possibly peroxide?) and using a symbol brush is an odd sensation as someone who always wets my toothbrush before using. My gums were not irritated and I did not experience any negative effects from using this product, but overall, not a drastic difference in the color of my teeth. It is possible that it needs to be used longer than the amount of time that I used though.