Helpful supplements?

Have any of you ever tried incorporating CoQ10, raspberry keytones, and/or l-carnitine to help your metabolism or lose more fat weight? Any other helpful supplements out there?

Please take into account that I DON'T believe in miracle pills. I believe that I must eat right and exercise to lose weight, but I am just looking for something to help with my metabolism. I have a family history of low hormone levels and under-active thyroids. My hormone counts are low, but not low enough to be put on medication, so I just need a little boost. :)