I have always used the teeth whitening system from my dentist however I found it difficult to keep up with the price. Seeing nano advertised and looking through their endless positive reviews I decided to give them a try. Firstly I was amazed by how quick there delivery was I literally recieved the product the day after placing the order. I love the packaging but most importantly the teeth whitening strips caused me absolutely no discomfort or sensitivity I use the an hour before I go out or an hour before bed they are so handy big difference from using the dentist whitening where I had to sleep with retainers in for 8 hours a night. I have used 7 strips and already my teeth are so much brighter. I do drink coffee so my teeth were becoming stained this has made a big difference. I'll continue using nano products so much quality for the price.