My teeth has become yellow.is there any medicine or tube or gel that i can use to whiten them?

Yes: Try crest white strips. They can help with the yellow look if your teeth.

Definitely!: It is not uncommon for teeth to yellow with time. You can whiten your teeth with whitening gel from tour dentist. With at-home whitening, the gel can be placed in custom made trays which are placed on top of your teeth. Another option is in-office whitening such as zoom whitening. With this the dentist places the gel on your teeth and then shines a bright uv light on your teeth to whiten them.

Yes, but first...: It's always best to first see your own dentist to make sure your teeth & gums are healthy. There are also reasons other reasons that your dentist should see you first. For example, bonded fillings and crowns do not whiten & if you whiten your teeth on your own, you might be in for a surprise.Your dentist can explain all the methods available to you & what is best for your specific circumstances.