I have used this product before and it provided dramatic results quickly. Easy to use, the mouthtray piece keeps solution close to teeth for maximum whitening. The plastic mouth/teeth tray is easy to form; boil water, set aside. Once bubbles from the boiling temperature reside, dip tray in for literally a few seconds, place in mouth to form - boom, done! Since tray only stays in hot water for few seconds, it in no way burns your mouth when it forms the impression of your teeth. Squeeze whitening solution into trays and leave in mouth for required time on box (30 mins or less). *It does seem that when I origninally began using the formula when it came out some years ago, that it was stronger or something, the whitening power has diminished just a little bit. Maybe some type of FDA law required less potency? I like this brand because I don't have to where anything overnight, don't have to use it several days to see results. I leave the trays in my mouth on a weekend morning before I go out, or in the late evening while watching a show or reading, etc. Unless I find something that has ultimate shock power white results, Dr. George's still works very well and produces whiter teeth in 1-2 same day application use.