This product got my attention because I have sensitive teeth and the product states that it has red/blue light to make your teeth not get sensitive after the whitening process. So I bought it because I really wanted to know if it would actually work, whitening strips make my teeth HURT even the ones that say “for sensitive teeth use” . My teeth weren’t too yellow, this product comes with a little scale to see how white or yellow your teeth are mine were about a 3 to 2 depending on the tooth I was looking at.So when I received the product I was a little scared to try it because the instructions said try not to get it near your gums or your lips because it will cause a burning sensation and it can be an irritant, but with the gel pen that it brings it gives you full control on how much or how little you want to apply the gel to your teeth, the instruction were just a tad unclear but it says to put the gel in your teeth turn on the blue light and that’s 15 minutes and then when the timer goes off turn it on back again and do the red/blue light and that’s 10 more minutes. So in total is 25 minutes, I saw a lot of reviews saying that they only use the blue light or only the red/blue light for a “quick whitening” but I followed the instructions to get the maximum whitening effect that this product claim to have and it worked! I am so happy with the results because it was an overall whiter smile after the very first use and no sensitivity, it also does not leave white spots on your teeth like regular whitening strips, it’s very even which I really like because in the past the white spots on my teeth after using whitening strips have always been a problem for me.I did try to use this whitening product 2 days in a row to see how my teeth would do, would they get sensitive? And the answer is yes, if you struggle with teeth sensitivity I would not recommend to use this product daily, it’s a little too strong at least for my teeth but they did not hurt nearly as bad as they do when I’ve whiten with strips however I cut back to only twice a week. And it’s been working for me, my teeth look a lot whiter and the gel pen is really convenient to use because I can get it in spots where the strips usually can’t reach.Also I did apply a little bit on my gum by accident once, and it did burn just a little. It wasn’t too uncomfortable or too painful either, but I try my best to not get any gel on my gums as much as I can. Also on the instructions it says that is BEST to refrigerate the gel pens, but I only got the current gel pen that I am using in the fridge. Doesn’t seem to really make a difference from the first time I used it without being refrigerated till now that’s been refrigerated. So I’m not too sure why store it in the fridge butOverall I give this product a 9/10 and the only reason why I give it a 9/10 is because the LED light mouth try is so sensitive to the touch and just by grabbing it it turns on. It usually always turns on at the worst times, just because the on button is so sensitive to the touch. I also noticed that the LED mouth tray needs to be charge every other use, but it charges super fast so it’s not a long wait at all.So overall great product, I will continue using it. I’m pretty happy with my results so far.