Which supplements?

[cakesandtea]

I am sorry if it was done to death.

Any supplements people found helpful in kick starting the slowed metabolism ? (I mean pills)

I know I need to exercise and reduce calories etc, and I intend to. When I was in my 20s I did all that but also used supplements that helped me to start and keep at it at the time. They just worked for me.
L-Carnitine
Coffee
Green tea
I remember I used some metal suppl like Chromium, or Magnesium, can't remember. Anyone has experience with this?
Anything that works well?