Review (3/5): Easy to use but didn't deliver the desired results
I followed the recommended initial use instructions, which involves repeated sessions over a period of days. I took a picture of my teeth each day to determine the progress. Unfortunately I did not have any visible progress. I didn't really care for having the timer/battery power hanging from my neck, but that is the only option if you want to be mobile. The change from each 8 minute session was a little messy, even though the whitening product is digestible, you still have an accumulation of liquid in your mouth, and taking the mouthpiece out and putting it back in is messy. The mouthpiece itself was surprisingly comfortable. I did have some gum sensitivity after the 2nd day of repeated use. Maybe this works for other folks, but not for me. The return was easy and the refund process was very quick.