Really surprised after just 5 days of use!
I picked up a travel size tube of the Colgate Optic to take on a recent 5 day cruise with my husband. I don't buy whitening toothpastes so that certainly wasn't my motivation in buying it - this was literally the only kind available at the drugstore at that time! Anyway, we went, we cruised, we ate and drank to our hearts content, and we did our usual brushing routine in the morning and at night.  We've been home for four days now (and have not been using the Optic as we used up our little travel tube) and for the last two days, I've been trying to figure out what the heck looks different when I look in the mirror. I finally clued in tonight - my teeth actually are a little bit whiter! At first I thought it was the ultra bright lighting in the washroom at work, but I noticed again tonight while brushing my teeth before bed. I'm quite amazed that half a travel size tube used for such a short time has actually made a visible difference!  Now, with that being said, I don't think this is something I would use as my permanent toothpaste for two reasons.  One, I have white fillings on my front teeth and I don't want to worry about them looking significantly different from the rest of my teeth, and two, my husband and I both felt a very minor bit of tooth sensitivity toward the end of our holiday.  Neither of us has felt that since we got home so I think the toothpaste was probably the cause of that. Given the results I have seen, I would consider using this perhaps every other day and just keep an eye out for any sensitivity down the road.  I am definitely one impressed customer!
Rating: 4 stars