I was so excited to get these so I tried it right away! I really liked how well these stuck to my teeth so I didn't have to worry about them slipping off while I was talking and I was even able to have a little water with a straw (2 hours is a long time!). I just wore them while doing some housework to kill the time. When I took them off, I didn't notice a difference right away but when I went into natural light I could tell that my teeth were a few shades whiter. Definitely not a drastic change but a decent one! I'd say this gives the same results in 2 hours that the 10 or 7 days strips give in their respective time frames. So it's just accelerated results. Don't expect you'll have a SUPER white smile in 2 hours. You may still have to use this a couple times to even mix it with a 7 or 10 day treatment if you want something more dramatic.

I was worried I'd have some tooth sensitivity since I got the impression these strips would be really strong and I sometimes have mild sensitivity. But I had no senstivity at all.

One box comes with enough strips to last a year. They recommend a treatment every 3 months so there's 4 treatments in total. I would purchase this because then you pay about $55 (less with a coupon) for a full year of whitening treatments! Not a bad deal at all. Other Crest treatments are like $30-40 but only last the week or so. All in all, I like it and I'd use this for my regular whitening routine!

Whitening strips work great if used ongoing especially if your a tea drinker or smoker. Its usually the cost that is a deal breaker in this economy.