My understanding is that ephedrine was one of very few drugs that had a demonstrated ability to increase metabolism and decrease hunger, at least when combined with caffeine[1]. It did so in relative safety, and the only deaths I'm aware of were due to overdose. Given the obesity problem in the US, I'm still amazed that it got banned.

[1] http://www.ncbi.nlm.nih.gov/pubmed/1318281