ephedra is the plant. the part of the plant determines the alkaloids present.
mu huang contains most alkaloids of ephedra and therefore has the best fat burning ability.
sida cordifolia contains second most alkaloids and is the second best at burning fat.
products that say ephedra extract ( leaves) are useless because no alkaloids are contained in the leaves.
if you cannot find sida cordifolia or mu huang, as stated before[ because they are banned from being sold in weight loss supplements], and, as you know, use ephedrine hcl/sulfate.
more info taken from bb.com
Herbal Ephedra and Pure Ephedrine both stimulate CNS and SNS to some degree. Pure Ephedrine, due to the lack of the 5 other alkaloids, has a MILDER CNS effect (less side effects / jitters) but still has SOME CNS effect while maintaining a powerful SNS effect.
Ephedrine Alkaloids (in herbal Ephedra):
(-) ephedrine
(+) pseudoephedrine
(-) methylephedrine
(-) norephedrine
(+) norpseudoephedrine
(+) methylpseudoephedrine