ephedrine, ephedrine, ephedrine, nothing burns fat like good ol ephedrine. Synthetic or the plant extracts. But..... As so far my customers are diggin the lipo6. Its a solid ephedra free. Added gugglesterones, time release (which is actually quite cool and does work) helps to prevent crash. Just know that synephrine is not ephedrine and never will be. Lipo6 is a strong stimulant and prob the best mainstream EF fat burner out besides AlRI's venom.