Review title is Works but painful! [SEP] I started using this a few weeks ago.  At first it wasn't painful hardly at all.  And it's true, after 3 days I was definitely noticing a difference and was very pleased.  But the last time I put them on it was so painful I had to take them off after 10 minutes.  I plan to go back to them again but am a little leary of the pain right now. However, my teeth are sensitive so this might not be the case for everyone.<br />Overall, very happy with the difference it has made in the color of my teeth....just wish it was less painful.