whatever works for the individual is ok, but I think we know that the best way to lose weight is consume less calories than we burn off. If you don't tackle the root of the problem, then even if the pill works (and it probably will), then as soon as you start eating normally, the weight will creep back on. Unless of course you start eating healthily again. And if you are going to do that, then you may as well have just done that from the start and save yourself a bundle of money in the process.
However, that is only my opinion, and I really do hope that it is different for you, so good luck.