Ephedra speeds up the heart rate. It has been known to cause heart failure and strokes in people who take too much. It also raises the blood pressure. Ephedra has been banned in a number of professional sports.
There are supplements out there that use the word "ephedra" but are actually ephedra free. Or the manufacturer hides it in the list of active ingredients by calling it "ma huang."
My personal experience with ephedra is that I had constant headaches, sweating and dizziness, my pulse was noticeably increased. I was not an active alcoholic when I took ephedra, maybe 10 years ago.