Do any fat burners etc work?

Has anybody found any supplements that boost losses and rip you up without muscle loss? I take a whole lot of vitamins, fish oils, fatty acids, extracts of this and that and blah but has anybody found anything new beneficial?
I worry that if i ever took a thermogenic pill that stopping taking them would mean my metabolism would be much slower than it was used to on the pills and i would gain weight rapidly? is there any sense in that? haha, thank you xxx