An amusing story, regarding ephedrine and its effects on sexuality:

After my girlfriend and I had been dating for about a month, she suggested that I try some mini-thins, promising that I'd enjoy it and that they made for great sex. I took some, and she took some, and we waited for it to take effect. We took good advantage of the time for some very entertaining foreplay, and I at least was vastly disappointed to discover the effect that ephedrine has on the male sexual response: the spirit is more than willing, but the muscles are far too relaxed.

However, this muscle-relaxing effect is perfectly complementary to female sexuality so far as I can tell, and my girlfriend was perfectly capable of enjoying herself. All I can say is, thank the gods for the human tongue; it's one of my favorite portions of my anatomy.

As a side-note: Ephedrine can help reduce muscle tension, though is probably not the drug of choice for doing so, and can do wonders for a tense and sore neck and back. Additionally, it acts as a bronchial dilator, increasing lung capacity temporarily. Unfortunately, this combined with the "high" ephedrine gives also makes smokers want to smoke more.