I was given one set of crest whitestrips in a giftbag. and there is no directions on them. So what do i do? and, do they even work?
I actually have the stuff that I got at the denist when I got mine zoom whitened and I have the touch up kit. And its 9.5% peroxide and I leave mine in for an hour or longer it gets them whiter and they stay whiter longer. The only draw back is my teeth become sentisve when I take my treys out, I mean I can suck in air and it will send a chill down my spine, but I don;t think theres are nearly that strong. So you can leave them on for I would say at least 45minues to 1 hour to see how that have progressed and if there not as white and your teeth aren’t hurting put them back on for a little longer.
Hope this helps! Goood lUck
6 years or whatever it says on the package