I don't think you have to worry about it. But if you get a stomach ache seek medical help.
Yes they do. I have listerine whitening strips that are expired. There should be something on the box.
considering whitening strips contain chemicals there is nothing natural about them.
The reason you feel hurt when you use teeth whitening strips maybe because you have sensitive teeth. In other words, the chemical overact in your gum and that's the reason why you feel hurt!
It is recommended to avoid smoking after using whitening strips as smoking can stain teeth and counteract the whitening effects. It is best to wait at least 24 hours after using whitening strips before smoking to maximize the results.
They are made out of mint
Crest Whitening Strips are used as a popular alternative for whitening teeth. The ingredients include: Water, Glycerine, Hydrogen Peroxide, Carbon 956, Sodium Hydroxide and Sodium Saccharine.
Yes, you can.
I like Crest Whitestrips Seals better
About 20 dollars to 40 dollars
I don't think this is ok, girls at that age are young enough to improve their teeth and using whitening strips isn't a good habit to start.
After you remove the teeth whitening strips there will be excess residue on your teeth left over form the gel from the whitening strips. As the whitening gel gets to work it foams up (which is the oxidation process that whitens your teeth) so it will spread out across your teeth. The best thing to do is to gently brush away the gel from your teeth using a soft toothbrush and your normal daily toothpaste - this will remove the left over whitening gel and freshen up your mouth.
Before, of course. Brushing your teeth removes build up of food, plaque and other nasty things. So do you want to whiten your teeth, or the nasty gunk on top? Also, if you brush your teeth afterward, it might not let all the chemicals do their complete job.