I've been using Crest Whitestrips for years, ever since the original product was released. Crest continues to refine the product, as it becomes more powerful, requires less time, and with better adhesion. I'm at a point now where I just use them for a few days every couple of months for upkeep. Their effect is noticeable, both to me and to friends who comment on how my teeth look whiter. Without regular maintenance, my teeth would be fairly yellow and dull-looking. No, Crest does not give me the blinding, "Hollywood-type" white, but that's not what I want, anyway. Instead, they look bright, natural, and definitely more white than yellow.

It keeps my beverages cold and hot like it should, but the lid sometimes leaks a little when I drink out of it.

Somebody gave me free sample. I got a headache and my heart was beating fast for hours. I drink strong black coffee everyday and it doesn't do that to me. Buyer beware!