Many supplements will "help," but will play a VERY minor role when compared to primarily diet, then exercise.
Presumably if you're supplementing with ephedrine, your primary goal is fat loss? There are all sorts of supplements which supposedly aid fat loss (green tea extract, ECA stack etc.) but as far as I'm aware, the only one which has any SERIOUS effect is ephedra (not to be confused with ephedrine), which I believe is now available to purchase again.
Remember: diet is by far the most important thing, then exercise. Supplements play a very minor role.