Hardens too quickly, bad packaging
The dispenser didn't hold up long enough for me to be able to get any whitening effect from the gel. The gel apparently hardens fairly rapidly, so after a couple of days it was very difficult to push in the plunger to squeeze out the gel. In fact, the plunger broke, so I tried to grasp it with pliers and pull it out. I then had to use a q tip to dip in the tube and apply the gel. It was quite a mess, and I wasn't able to do this more than 4 or 5 days. I could feel the gel tingling on my lips, so I think it was probably working, but the packaging was a poor design. Maybe I noticed a shade whiter in the few days I used it, but definitely not worth the mess. You also do need to separately buy a reliable tray to keep the gel on your teeth.
Rating: 2 stars