Ephedrine is a stimulant ingredient, belonging to a group of medicines known as sympathomimetics. Specifically it is both an alpha and beta adrenergenic agonist (you may remember Clenbuterol is a selective beta-2 agonist). In addition, ephedrine enhances the release of norepinephrine, a strong endogenous alpha agonist.

The action of this compound is notably similar to that of the body's primary adrenergic hormone epinephrine (adrenaline), which also exhibits action toward both alpha and beta receptors. When administered, ephedrine will notably increase the activity of the central nervous system, as well as have a stimulatory effect on other target cells.   More detail...