This product is cost effective and works as described. I gave it 4 stars for 2 reasons. The first is the trays seamed to shrivel up the moment they touched hot water. I was still able to use them, but they could be improved. The second reason is that while I understand the instructions are written with safety in mind, other than the "irritation test" they should have you use the product for 45 minutes rather than 15-45 max. What they don't tell you is that the Carbamide Peroxide must break down into 2 parts once applied to your teeth. One of those parts is Hydrogen Peroxide which is what actually whitens your teeth. (44% carbamide results in about 15% hydrogen peroxide solution) The break down process can take up to 15 minutes once applied and it isn't until then that the whitening begins. For those that only do a 15 minute session little to no whitening is actually occurring.

Love this kit! This is after three uses-2 min, 10 min and 15 min. I bought the remineralizing gel and my teeth are affect at all. I used crest white strips and my teeth were so sensitive for months. With this, I literally experienced no sensitivity at all! High recommend this!! You get so many uses out of this. I've had three treatments and I've only used half of one tube and it comes with 5

Great buy worked well, very strong. Burns a it, beauty is pain though.

Within 3 treatments I went from dingy to movie star white!!! I thought I would never get the "professional" for "affordable"! I've tried so many and this really works

I've had my teeth professionally whitened in the past. I was looking for a cheaper way to obtain the same results. So far I'm very impressed with how this system is working. I will definitely purchase this product again when I'm out of gel.