Do any of the side affects include brain damage?
Will your body become dependant on these tablets and then when you stop taking them you won't lose weight naturally because you rely on the tablets to do so?

It's mostly dependence I'd be worried about
Ecstasy was originally a weight loss pill, as was many amphetamines
if you don't become chemically addictive, you will still be used to 'taking the easy way out', you should work for it