Review (4/5): Effective, Slowly but Surely
This is subtle, so far, but it works. I've also only had it for 2 weeks, and I drink lots of tea each day (which is why I need it!), so it may have more of an effect as I continue to use it. But it definitely brightens your teeth and is obviously gentler than the harsh bleaching products I've used in the past.
It's pricey, though, so not sure if I'll buy it again once I've finished.