I inquired about teeth whitening at my dentist office and they suggested Crest white strips. They explained that they work well and unless I had a big event upcoming (wedding, photo shoot, etc) that the white strips are appropriate.
This is my second order of white strips and I can say that the first go around I noticed a difference in my teeth. With the first box I used them every day for 14 days straight. There was a little bit of sensitivity in a couple of teeth but nothing unbearable. I ordered them again and now I use them once or twice a week (mainly because of the sensitivity). I haven't noticed any improvement since the first box.
There are only 2 issues I had with them:
1. The directions doesn't explain is how long to use them. Like should I have gotten another box right away? Is that safe? *shrugs*
2. The bottom strip is short and doesn't whiten as well as the top teeth strip.
The Amazon price was reasonable vs. store price.
All in all I like them and would order them again.