Probiotics- There's nothing like putting the right stuff in your body, especially when it's packed with good bacteria. While for some it may be increase the level of metabolism in their body, it could be to actually supplement a particular vitamin or mineral for some others. Also by making small changes to the amount of moving you do will boost your weight loss results even more.
The best way is to consult with your doctor, but if you don't do that then you should do some research before purchasing anything. Typically, fat blockers like Alli and Xenical are taken three times a day before eating. True, your body functions in the same way as any other body would but it is also home to its own quirks.