If you're not losing weight, it's your diet. You need to mix it up. Just eating good doesn't necessarily mean you will lose weight. Simply adjust your diet, and see if you can get your results sooner.
In my opinion, as well as the opinion of everyone else, diet pills are nothing more than a inconvenience to your time, effort, and money.
Simply put, your time will be wasted because you got your results sooner, but later you will regain what you lost. Therefore your time is wasted effort because you went back to where you started.
Your effort is wasted because instead of exercising and dieting like a pro, you decided to take the easy way to get a temporary result. Your effort is further wasted when you regain the weight after not taking the pill and having to refocus on why you regained the weight.
Your money is wasted because you spent money on junkie pills rather than on more valuable things like a bottle of multi, or something. Your money is further wasted because you could have bought good, natural food that could feed you for weeks. Your money is further wasted because you could have went and bought a brand new pair of weight belt to pump up your exercise to the next level.
All in all, I say sit down, look at what your exercise and diet are like, and make adjustments. Try running some, or another cardio exercise to jumpstart your fat lost. Or look at your weight training, try to see if perhaps you can add more weight, less/more reps, or something. Look at your diet. Perhaps you're eating the same as you did or maybe you need to adjust your eating habits before and after your cardio/weight sessions.