Honestly, I always want a whiter smile. These whitestrips worked GREAT for me--within only 2 days I felt like I could already see results! They are sort of a splurge for me, but you really only need to use them twice a year to keep up the white smile; however, I got a coupon for some money off my next purchase of the whitestrips (as well as coupons for the advanced vivid tooth past, toothbrush, and whitening rinse--none of which I've tried yet). It takes 2 weeks (14 strips for top AND bottom), but its well worth it. Like I said, this product worked REALLY fast for me! I'm definitely pleased with the results and couldn't ask for better :) (hint: if your teeth are prone to getting sensitive like mine are when using white strips, I recommend using Sensodine toothpaste [or any toothpaste meant to decrease tooth sensitivity] for a few days before and throughout the two weeks you use this product; it kept my teeth from hurting at all!)