No quick fix has ever proven to truly be effective and safe. There have been several such products on the market over the years that turned out down-right dangerous. Dinitro phenol has a funny habit of reappearing periodically. It does work by increasing metabolism, but also fever and has caused death from hyperthermia!
I know it sounds self-serving, as a physician suggesting this, but no one should attempt to lose weight without being under the care of a health professional who is licensed.
It's a temporary fix, just like dieting. No good in the long run. They're a lot of good herbs out there that can help you lose weight combined with exercise and eating clean.