I would be insanely hesitant to use such a pill, eventhough my own dog is grossly overweight(yeh, I admit it... I can't stand it, but the whole family has to cooperate before we are able to get him back on track.).

Think about it. How many times have you heard of diet pills for humans that ended up not being safe? If its so common in pills for humans, I sure wouldn't take that chance with my own dog.