Europeans are deservedly best known for their ugly royals and bad teeth. So it is with all due humility that I recommend a teeth whitening product.
There is really nothing very fancy about Go Smile. It is just hydrogen peroxide (and iodine). The insight of the dentist that brought it to market is that don't need that much hydrogen peroxide (bleach) to get white teeth. So you don't have sit around wearing some device whilst trying not swallow. More importantly, the sensitive of teeth and gums (me) can use Go Smile without any discomfort. Most importantly, it works. Even for people who drink black coffee and red wine (that would be me, again).
I found that it is a good idea to use one ampoule a day for the first week. Thereafter, I was able to cut back to twice weekly maintenance. The other day my dentist complemented me on my teeth. True, she is Russian.
I have also switched to Go Smile toothpaste. In a crude attempt to make you buy two tubes there is one for morning and one for evening brushing. I use PM for both. The whitening agent is white cranberry powder. I bought my husband a tube the other day (he was beginning to look like a recent immigrant from the Ukraine). There was a noticeable improvement within four days.