I am not a fan of the Bella Brite Teeth Whitening Trays. They are very costly, inconvienant, taste horrible, and don't even do the job they are supposed to do which is whiten teeth. Effectiveness I tried the Bella Brite Teeth Whitening Trays, and was very disappointed. They did not whiten my teeth at all! I went through the time consuming process, dealt with the horrible taste, the the uncomfortableness of having the trays in my mouth all for it not to work! I would not recommend this product to anyone. I don't smoke, I don't drink coffees or tea, I don't drink dark red wines or anything else that would stain my teeth and this product still didn't whiten my teeth anymore than what they already were. Convenience The Bella Brite Teeth Whitening Trays are not convenient at all! I have to have the very uncomfortable trays in my mouth and leave them there for thirty minutes before it will work. I don't have thirty minutes to waste on a product that does not even work. Minimal Side Effects I would not say that the Bella Brite Teeth Whitening Trays have minimal side effects because I can still feel my mouth hurting for hours after sitting with the uncomfortable trays in my mouth. They were very painful and my teeth never even got whiter after going through with the whole process.