use the real xen, i dont even know why they made that other shit. probably because there are pussies who are afraid of ephedra, which makes no sense whatsoever. ephedra is a non specific beta agonist, and i dont really see how it can harm anyone. it isn't like clen, which i belive causes beta 3 receptors (maybe beta 2, not sure) go inside the cell. eca actually becomes more effective the longer you use it. no supplement will give you great results without a good diet. the caffeine is added to stop the breakdown of cAMP, which is created partially because of the ephedra so it really would be of no benefit to take caffeine without the ephedra. i belive studies have shown that caffeine by itself can cause weight loss, but it isn't signifigant and wont have any muscle sparing effects like e+c will. I seriousley doubt that you will have any bad side effects from xen or any eca product as long as your dont overuse it.