I had my teeth professionally whitened about five years ago. Since that time they have dulled in appearance, and I have been waiting until I was not pregnant or nursing to try an over-the-counter whitener. My budget turned me to Crest Whitestrips classic.
I am on my fourth day of using these whitestrips, and I can really tell a difference already. They give you enough for 14 days, but I can already tell I won't use them all and will either use them for a quick brightening at some later time, or give them to my husband.
These strips are relatively easy to apply by peeling the backing off the strip, which is loaded with the whitening gel, and placing them across your teeth.
You leave these on for half an hour, then remove them and rinse. There is no bad taste once you remove them, and I don't even feel I have to brush my teeth as long as I rinse my mouth out well enough.
These seem to work really well, and relatively quickly.
As with any tooth whitening agent, I have noticed quite a bit of tooth sensitivity. But, my granny always told me that you have to suffer for beauty, so it isn't that bothersome.
These are pretty goopy, and I find it best to make sure I don't have to speak while I'm using these strips. If you are thinking of whitening while at work, etc like some of the ads suggest- forget it.
Overall, I recommend these highly. They are a relatively inexpensive way to take a few years off your appearance, and freshen up your smile.