No pain, no gain?
I found this kit on Groupon for $5. Yeah, I know...for $5 I was just hoping it didn't melt my teeth. The kit itself came packaged and unopened. I would find it disgusting if it looked open/used like other reviewers stated but no issues with mine.  Boiling the trays to mold to my teeth reminded me of my football and hockey days when I had to do that to my mouth guard.  Anyway, I boiled it for a few seconds longer just in case it did happen to be tried out on the production line -for quality assurance. It fit my teeth nicely even over my snaggletooth. The instructions says to trim the guard away from your gums. THAT IS THE MOST IMPORTANT PART. It comes with 10cc of the solution. And it actually suggests to use half of the gel on each tray. I decided to go with about an 1/8th the first go round. It immediately started burning and I realized I didn't cut down enough along the gum line. I tougher out the 12 minutes though with the light sticking out my mouth. Very attractive look. If your light didn't work, did you remove the plastic piece from the battery compartment? I just now finished my 3rd treatment and I have about half left. Ive trimmed down the guards a few times now. I must have tiny teeth.<br />Anyway, I have noticed some whitening already.  Tomorrow I'm going to go all out and finish the rest of the solution. If my mouth falls off or catches fire from the burning I'll come back and update the review. Otherwise, if I don't it means it worked as well as a $5 whitening system should work.
Rating: 4 stars