The exciting medicinal effects of mahuang originate from two alkaloids, pseudoephedrine and ephedrine, that gather in the nodes of ephedrine hydrochloride stems. Ephedrine molecules strongly resemble the molecules of epinephrine, or adrenaline, and attach to exactly the same chemical receptors in the body. Ephedrine creates an artificial adrenalin rush, causing the responses your body would require during a trying physical crisis.