★★★★★

"I’ve used a fair amount of expensive teeth whiteners over the years and olü has to be my favorite. I bought the kit and saw a real difference in a week! It’s the only teeth whitening solution that makes all of my teeth whiter, not just makes the dark spots and stains more obvious while the other parts of my teeth are whiter. I'm definitely getting the refills and will continue to see if I get improvements."

-Andrew M