Review (5/5): Didn't expect much, but after about a week of ...
Didn't expect much, but after about a week of using it twice a day, my teeth are noticeably whiter. If the trend continues then these do exactly as advertised. Careful if you brush vigorously though, you'd be surprised how dark this powder is and how far your brushing can launch it. It's water soluble though so it doesn't stain anything.