It really worked for me. I saw a differnece after just the first application! With other products sensitivity is usualy an issue for me - but this product was great- no sensitivity. The one con - the trays are a bit floppy and don't fit as well as some, but hardly an issue for me because the whitening formula worked so well.

I used Rembrandt as instructed and my teeth still yellow .I want my money back !

It did work and my teeth were a bit lighter after two hours. However, during the second application there was about five minutes of absolute AGONY. I didn't want to waste the gel so I didn't stop use and just braved through it. My teeth felt absolutely fine afterwards so the effects were def. temporary. I also had a tiny white spots on my gums that disappeared after ten minutes.

i used this right away and i noticed a difference. nothing drastic tho. it took a while to do which wasn't fun but i figured it was worth it. yes it will hurt if you use to much and get to much on your gums. but use the right amount and you'll be fine.

My teeth weren't super stained, but they also weren't anywhere close to white. After two uses there was a noticeable difference in color. Now I'm close to being at a white shade. :) I'm verry happy with that, but... The reason why I wouldn't reccomend this product is because of the pain, or the reason I stopped after only the second application. I had to cut the second session short 5 minutes because I was in such pain I had to spit the trays out and rinse the product off. I used the product as directed, making sure none got on my gums. The pain wasn't in my gums, it was one of my teeth on the bottom row. It felt like someone was pounding the tooth out from the bottom. It wasn't a constant pain, but it's been about a half an hour now and it's still coming and going.

I've tried many whitening products including the Zoom treatment. My teeth are stained yellow from coffee and cola. I used the gel with dentist-formed trays, and I was able to get a two hour treatment from TWO ampules, meaning I got four two hour treatments out of this box. You don't need a lot of gel at all, and if you feel sensitivity, you're just plain doing it wrong. I would estimate my whitening at two shades at this point, but having done plenty of whitening in the past, I know that you'll only know your final shade 1 or 2 days later. One trick I can suggest is to stand at the sink and with the water running, wet a Q-tip and clean off your gums, rinse, repeat, rinse, repeat until you're sure they're clean of gel. You don't want this stuff on your tissues. Will definitely use again...since I have three more treatments left!

I was very impressed by this product. I had no problems with getting the molds formed to my mouth & they felt very comfotable. There was enough gel in each capsule, that I was able to use one for both upper & lower molds. I did two sets of whitenings in a row & spread this throughout 4 days. I didn't experience any burning or sensitivity at all. While my teeth weren't really discolored in the first place, I saw dramatic results & can't stop checking my smile out in the mirror!! I love my pearly whites!! I will definitely purchase again in the future.

I think this product does what it says. The only reason I didn't give it five stars was that there really wasn't a "Wow" factor but it definately whitens and my teeth feel clean and smooth. Another plus is that each tube holds enough gel for both trays each use so it doubles the usage which is VERY nice since I'm cheap and this really is a luxury product during this time of the bad economy. I'm actually buying another two boxes[...]

I'm heading to Las Vegas tomorrow, and at some point meeting up with a party of about 30. I have pretty bad social anxiety, so I'm often nervous about my apperance and things of that nature, so I figured I'd whiten up with this product. I bought the product yesterday. I carefully followed the instructions and although the last capsule seemed to be a little painful, I was pretty satisfied with the results, and found it well worth it, considering it only took 2 hrs. Boy was I wrong! Last night I awoke in the middle of the night unable to get back to sleep because of the pain shooting through both my teeth and gums. By noon today, my teeth were quite a bit better but it feels like I raked a cheeze grater across my gums. By this evening, it not only feels as though I raked a cheeze grater across my gums, but it looks like I did. Seriously! My gums look all torn and well... hideous. I can hardly eat anything. I'm certainly not even going to consider brushing them until I see a HUGE improvement. I can't even smile they are so painful, and I can barely talk. My vacation is not something that can be postponed, it's a once in a lifetime thing. I'm really devestated about this. I had NO idea there was any risk invloved in using this product. "Sensitivity" is one thing. Feeling and looking like you've rinsed with some sort of corrosive acid, is another.

the product worked great. my gums got a bit sensitive so i spaced the process throughout a few days. i noticed my teeth were whiter the day after i finished using.