Great product! My teeth are so much whiter... people are even commenting on how nice they look! My teeth looked a shade whiter even after the first use! I used the product for two weeks twice a day for 20min a time. I would really reccomend this product, the results are exellent and it's really cheap. I have used non bleach whitening kits before, they have been no where near as good. If I was to purchase a whitening product again I would definatly choose plus white bleach, I would like to try the 6% version (this product is 3%).
When used correctly I felt no discomfort or sensitivity at all, I did however by accident once let the product get on my gums, be warned, this caused my gum to be very uncomfortable and the tooth near by to hurt. After reading reveiws before I purchased the product I was put off by some people saying how uncomfortable they found it, perhaps this is where they were going wrong.
I am now using the product on average once every 3-4 weeks, and am going to consider using it less now... google 'enamel decay' to see why lol!