This might be a good thread for you to read:
The basic answer is that pills don't work. If you visit our maintainers forum, you won't find anyone who has lost weight and kept it off as a result of a pill. I've read that the placebo effect for pills is generally around 50 percent but if the marketing is really good, then it goes up to about 75 percent. That means that the pill could have nothing in it and 75 percent of the people would think it helped them lose weight.