Does it work?

No. There is no evidence that ephedra products enhance athletic performance and little evidence of any benefit except for short-term weight loss. In small trials lasting a year or less, ephedrine combined with caffeine appears to promote weight loss, but studies of ephedra alone have been equivocal. The majority of weight loss trials have had problems with the methodology, including large dropout rates due to adverse effects and incomplete reporting of blinding or randomization.

Ephedrine has been shown to be helpful in managing asthma symptoms. However, ephedra supplements have not been systematically studied for these indications.