5-6 lbs in 3weeks?

There are so many diet pill reviews online that i been reading today, however i'm still a bit confused on which one to get because they said some of these diet pills are not working to some but it does for the others. I don't want to spend my money for product that it does not give me good result. I already been that postion before and it just so frustrating even more to think that i'm being scammed. I need to lose weight bad, my main goal is to take off 5-6pounds in 3weeks. Isn't it possible?