Review on Whitening Syringes Carbamide Peroxide Bleaching by Nancy Young

I've used 22% carbamide peroxide a few times and it can last over a year if stored properly. My husband and I have used it and left it overnight for several days in a row. We don't have the slightest bit of tooth sensitivity, which is unheard of. I just did the oxidizer text on 3 different syringes all negative. This is not a carbamide peroxide percentage. I found the syringes unusually large and versatile. I suspect they were filled with glycerin etc. I think this product is a scam or the seller exchanged it. I don't know who and how, but you don't say that.