definetly works [SEP] this system definitely works to whiten teeth everyones teeth are different and i imagine everyone gets very different results but it is not snake oil it does do something i have very sensitive teeth and have steered clear of whitening for years during the pandemic i have found myself drinking a lot more tea and that has really discolored my teeth and was starting to get embarrassed about them i bought this device since so many people say it is good for people with sensitivityi used the device as instructed it never bothered my teeth at all it did start to irritate my gums a little but nothing too bad and only while i was actually doing the whitening what i did find is that i was incapable of keeping my tongue completely away from the whitening product especially because there is a lot of saliva build up and spitting involved it really hurt the tip and side of my tongue on the days i was using it i had to stay away from certain foods which was a bummer after the recommended days of use my teeth were absolutely whiter i did not have hollywood level whiteness but they were a lot better than they had been and i was no longer embarrassed i could have gone on and done more whitening but my tongue could not take it anymore i will probably go back in a couple of months and do the process againi feel like i can definitely recommend this to people with sensitive teeth i think everyones whitening level will be different some might be more or less than me but it does work and depending on your level of tolerance for the whitening product you can likely get to your desired level