I've heard it is helpful and if you will use it properly you will notice a whitening effect on your teeth in only 2 months. Of you can go to a dental clinic, where you will have your teeth bleached by a dentist, but of course this procedure is pretty expensive but qualitative I might notice. Take your chances and try it because you will like it. Just be sure to find a good clinic like
thehealthysmile.net where you can find the best specialists in town. I always cure my teeth at their place, because they have quality services for a pretty small price, furthermore, you can even get some discounts on their place.