I do not recommend using fat burner pills for aiding weight loss. They are stimulants, and as soon as you stop using them, their effect goes away, so you have to keep using them.
Fat Burners will make you want to eat less, and for most of you, that is not the goal!
Fat Burners also cause you to feel more stressed because they elevate your heart rate, which could cause more stress hormones to be released by your body and make long term weight loss harder!
I say avoid them!