I am size 8 and my weight is 153. I have an hourglass, so I am happy with my figure. I am 5'6". Two years ago when I was 143lbs & size 6, If I needed to go down to a size 4, 135-138lb for a special event or for a beach vacation, I would do it with the aid of diet pills. Here is my experience:
I have tried Phentamine (good for a jumpstart on weight loss or for the final 10 lbs). Good energy boost also.
Zantrax 3 - Poison - I had an instant headache and my stomach felt woozy. Took the bottle back to the drugstore.
Diet Fuel - Now that was a good diet pill. I was shocked when the FDA banned it and I through out the bottle - My life and my health are more important that wearing size 4.
Xenical (Didnt work at all b/c it only helps people that eat a lot of oily food - my weight is from sugary food, I don't like greasy or fried food).
Meridia - The best diet pill that you can buy-hands down. No hunger, no scary side effects.
Keep in mind that diet pills are for short term use only. Don't even think about using them if you arent under the direction of your doctor. I stopped using the diet pills when I realized that I could hurt myself or could mess up my metabloism with it. **Also, even the best diet pill becomes ineffective after a month or so b/c you body will adapt to it. So use the diet pill that your doctor recommends only to help spark your diet & exercise plan.