What kind of pills can a eleven year old girl take to lose weight?

nothing that is remotely FDA approved.

You should not take pills to lose weight!

If you want to lose weight, you will have to do it the healthy way, which is to eat healthily and to exercise.

Pills that claim to help you lose weight don't actually work - they generally remove the water in your body, which makes you "shrink". And losing too much weight too fast is dangerous. You need to build muscle. Plus, it could potentially lead to saggy skin.