Noticeable difference in the brightness...
I have a nice shade of white teeth as it stood already. This is mainly due to routine usage of the Crest Supreme Whitestrips (once a year, I'll do a box) and I brush with a whitening toothpaste (either Arm & Hammer or Crest Vivid) daily.  However, it wasn't until I used this product did I see a noticeable difference in the brightness of my smile. I won't attribute it to my toothpaste since I've used both brands for over a year with no real oomph~ except for maintenance.  So I started using this a month ago.  The directions say to add it to your toothpaste as a booster; but I brush with it after I've used my toothpaste. It's a clear, tasteless, thin, gel formula that is not runny in consistency.  The one month end result is much brighter, white teeth. Darn that was fast. Only compelled to write a review since my bottom teeth had never reached this level of whiteness; even with the consistent use of the Whitestrips throughout the years!  So pleased and will keep it in my arsenal.
Rating: 5 stars