I personally don't see anything wrong with ephedra, it had been used for thousands of years until some people abused it, dehydrated themselves and mixed it with high doses of caffiene and other stimulants. As long as you use it in moderation and keep hydrated, most people do fine. I wouldn't drive under the influence of it until I know how it effects you though, my college roommate got very nervous while using it.

honestly, I wouldn't use those pills at all.
Weight should be lost with diet and exercise. And I don't mean diet as in all you eat is salad. Following the daily food requirements. If you can't lose weight that way, often times people just gain it right back after you use those pills. if lifestyle doesn't improve, you wont keep the weight off.