I have already seen significant improvement in my tooth coloring

Lifetime of coffee and soda. So, not only do I have a bunch of cavities, but my teeth have been yellow as long as I can remember. Not the first whitening I have tried but definitely the most convenient. Crest whitening strips, how much you drool and how much the strips move were always a waste for me. Having the trays with KOR absolutely helps me stay on track and not get annoyed. I am 6 days into the 4 week program and have already seen significant improvement in my tooth coloring. I will be excited to see where things end up when I am done the 4 weeks and the in office session. My teeth aren't overly sensitive so there has been minimal pain so far. Mostly just the initial burn of the gel on my gums where I missed wiping it off. I will be sure to upload before and after pictures when I am done. The reviews that I am seeing where it WASN'T worth it (where there were actually pictures) appear to be on people with teeth that are already pretty white.