This is what I find attractive. I saw a study showing that 22% carbamide peroxide gel is the most effective at whitening.
What you do with these guys is they send you an impression piece. You make an impression, send it back, and they send you two trays (upper and lower) and the gel.
hands down,...this place. I am a person that believs you get what you pay for, but there are small exceptions if you can "find" them. I did some research on my own, was searching for the same thing without all the high bs dentist fee's, and tried to see if I could just get the whitener products they sell on my own. I found this place, and my girl wanted to try them out first. They sell the same identical products that the dentist gives to you for take-home professional whitening with a mouthtray. You take an impression, mail it back to them in the envelope they send you, and they send you a custom fit professional mouth tray(s), you can use over and over again. All this along with the product. (professional grade, carbomide paroxide, brand name teeth whiteners dentists use/ sell) Now with a dentist, you are going to pay all those additional fee's for the custom tray, the visit, and his markup on the products. Her teeth were noticibly whiter in less than 2 weeks. Really great stuff, as I am next. The place is really good.
We used the Achromasia 22%. This seemed to be one of the most popular brand names, with the best results. Having the least amount of tooth sensitivity/ and or discomfort as sometimes it is common top experience symptoms like so as your teeth get whiter in the process.