These whitening strips changed my life. When I was in high school, my gay best friend told me that I had yellow teeth and my self-conscious teenage self bought these. Five years later and I still get compliments about how white my teeth are. If you're an avid coffee drinker, these will take away those yellow stained teeth. The strips are easy to apply, but they do produce quite a bit of saliva. The only con is the taste of it, but it does not matter at all when you see the results. I 100% recommend them!