PHILIPS Zoom Nite 22% Teeth Whitening Gel (White)

Worth your money

I used it 2 nights in a row and noticed a difference in just those two uses. My gums became a bit sensitive and I haven't used it since. I will use it again tonight though since my gums are back to normal. I did use sensodyne toothpaste in my retainers for about 30 minutes beforehand (as one of the reviewers recommended). Not sure if that helped or not (because it could have been much worse had I not done that). The only real sensitivity I noticed was when brushing so it isn't intolerable. I've had this happen previously and apparently it has to do with the % of the Whitening ingredient (of which is 22% - which is high I believe). I would definitely recommend it.