I'm going to keep it real and say it won't lighten your teeth 6-8 shades, in one setting. But you will definitely begin to notice a difference the more frequently you use it. We tend to eat and drink many foods that have dyes, it's hard to keep away from dyes on food; this product helps maintain a white smile after you have had a whitening session. Remember that this product only works--if you do. Keep up with the proper maintenance, especially if you're certified as a teeth whitening professional. Your clients will be inspired by your example. It's effortless for them to believe in your work if they see you being consistent. Much love! Enjoy the product!!!