People take 'weight loss pills' cuz they think they will work - basically they see the ad on TV & buy into it. But here's the thing - you didn't gain your extra 40 lb or whatever overnight and you didnt' do anything more than live a lifestyle that produced this result in your body. My point being that you can't expect a pill to force all the myriad functions in your body to "lose weight" immediately. The media likes to make it look that way but it isn't that way.
Go back to basics. You know the goal you want right? Your body responds to the lifestyle you live -- you can't force it to get anywhere fast because it always seeks equilibrium, but it also wants to run efficiently. That's the good news -- but you have to fuel it & exercise it so it will run optimally. If you throw in extra fuel that it can't use, then it will get stored as fat and your metabolism will respond by running sluggishly.
So again - back to basics. A hard part of the whole transition to understanding nutrition & "fitness" is getting past all these myths that the media perpetuates about fast weight loss, etc. It doesn't exist. Its not safe and its not maintainable. I highly recommend the BODY FOR LIFE book by Bill Philips - fantastic program - very doable, very flexable, not weird or expensive foods you have to choke down and not 3 hrs in the gym every day, AND it lays out the reasoning behind the fundamental notions of how you eat, what you eat and how much you eat to fuel the exercise to build muscle, reduce bodyfat, increase energy, optimize all your body's functions and generally get yourself to a better place.
One real easy truth about any pill or SUPPLEMENT - they are all just SUPPLEMENTS to an already well-established diet & training program. If those two things aren't in place already, then any supps are NOT going to do anything for you.