clenbuterol is not a strong a fat burner as ephedrine. it does last longer, which makes it useful because you get your beta receptors agonized while you sleep... soemthing ephedrine cant do(you cant fall asleep on it), but as far as overall potency, ephedrine KILLS clen. cclen is specific to beta-2, imagine a sniper rifle .. while ephedrine hits beta 1, 2, 3..imgaine a shotgun