I took an entire bottle (as directed...not all at once) so that I could give an accurate review of this product and not jump to any conclusions. First of all, you MUST take this correctly (30 minutes before eating with plenty of water) or you will feel sick. I took it correctly until the last couple of days and I can tell you that you will feel the difference. I don't know if it is a common side effect, but I did get a lot of gas pressure and bloating while using these pills. This was especially bad when the pills were taken after eating instead of before or if I didn't drink very much water with them. On the plus side, these pills DO curb your hunger! I actually had to remind myself to eat. I did lose weight (about 5lbs in the month) but when I stopped taking the pills, the weight came back. Effectiveness Very good at curbing hunger and giving you energy. Side Effects I was the most worried that these pills would make me jittery. They did not. However, the bloating was a huge negative for me.