I've been using crest whitestrips once a year for the last 15 years and they always do the trick! I remember when I first started using these they had an awful taste and never stayed in place. But now the gel remains adhered to the strips, which in turn makes the strips really grip your teeth. You can even drink a glass of water during your treatments. The only negative thing I have to say about these is that each treatment now lasts 45 minutes - the strips I used before were only 25 minutes.

They whiten your teeth. But if you have very stained or yellow teeth you'd probably need to get two of these. I use to use the supreme professional crest white strips that you can no longer find. Those were superb, and they really did an excellent job whitening my teeth. I purchased these as a substitute because I couldn't find what I really wanted, and yes they did whiten my teeth. I really noticed it after about three or four days but to be fair my teeth were already kind of white because I've been whitening for a while. But these do not work like the professional supreme strips so it's not the same level of whiteness, but if you're not used to really white teeth and you just use them for the first time you'll probably love it,

The only reason I bought these was because it was a few dollars cheaper during prime week, and I wanted to see if they worked. After using the entire box, my teeth were a shade or two whiter. I just wish the deals were better because whitening strips are so expensive.

Let me start by saying that I'm 28 years old and I never had my teeth whitened or even crossed my mind in doing so, I thought they look "okay" the way they were but boyyy I was wrong. This is a review with some info of my own experience using the product & to guide you on what you might expect and maybe help you with a decision. Aight, now I want to say that this product has impressed me soo much that this might be the longest review I ever wrote and no, I have not been sponsored or paid by this company, this is just my opinion and my honest review. Anyways, Crest 3D White Strips is one of those things that you didn't know you needed but trust me, this thing it's amazing. It went beyond my expectations and it's one of those products that I'll be buying on the regular from now on. Make sure that you are consistent and follow the directions when using it. The kit comes with 20 treatments + 2 One Hour Express treatments as a bonus. So it takes 20 days for the whole process plus 2 more days if you use the bonus treatments. One treatment per day and each treatment comes with 2 "whitening strips" one for lower and one for upper teeth.
Also a little DISCLAIMER : I took pictures of the whole process and under the same lighting at around the same time of the day, I tried to take the photos with the same angle but no angle is exactly the same. Due to this some photos might look slighty different and with slighty different colors. You might also notice some slight color variations but every phone screen is different. As a reference the photos were taken on a Galaxy S22 Plus. I will also label the photos so you know which part of the process they are from. The pictures were taken as follows:

1. before starting the kit (DAY 1)
2. Half way tru the kit (DAY 10)
3. At the end of the kit (DAY 20)
4.after using the 1 Hour Express (DAY 21)
5.after using the 2nd 1 Hour Express (DAY 22)
6. And last, a picture from before starting the whole kit and a picture from the very end of the whole kit including the 2 One Hour Express.
(DAY 1 & DAY 22)

So to clarify, I used the whole kit including the 2 bonus treatments back to back but I don't think you have to do it exactly that way; I think is better if you use the 2 bonus treatments down the line, maybe a few months after the regular kit to somehow "extent" the whitening effect..? I think that is the reason why the whitening effect is less noticeable on the 1 Hour Express photos than the regular kit photos.
Also on another note.. You might have seen on the reviews that you get sensitive teeth while using the kit, this is true but is not as bad a you think, at least for me it wasn't. In my experience I had sensitive teeth on some of the days that I used the kit but it goes away in a hour or two after each treatment. Sensitive tooth paste should help but dont let that discourage you cuz the end results are soo worth it !
Now, I want to end this review by saying that this product is worth every penny and I 100% recommend this to anyone. Also the pictures SPEAK FOR THEMSELVES ! I hope this review helps you on making a decision . SMILE life is good, have a good day ! :)

I remember when whitening strips had this nasty tasting gel that would get everywhere. These strips do not have that and are virtually tasteless. It was so nice to not have to hold my tongue up to the roof of my mouth for 40+ minutes to avoid the taste.
I have not had these long enough to see how well they whiten, but I do know that they have a great grip, stay in place, are easy to mold to your teeth, and are easy to remove. They don't leave too much residue and it comes off very easily when you brush your teeth. I used it in addition with a tooth whitening UV light and did not have a bad reaction to it. Very happy with this product.