During my sports science studies when i left school i did an in depth essay on many steroids, I have pasted some extracts from my studies on the drug you mention below. All of the below I then had to proove with real life cases, which wasntd too difficult in a gym full of doormen! :-)

Ephedrine belongs to the group of sympathomimetics. Although it is not a hormone compoun it offers the athlete three interesting effects.

On the one hand, this occurs since Ephedrine produces heat in the body (thermogenesis). Simplified, Ephedrine slightly increases the body temperature. On the other hand, Ephedrine stimulates the thyroid gland to transform the weaker LT-4 (L-thyroxine) into the stronger LT-3 (liothyronine. Competing bodybuilders have appreciated this for quite some time. Second, Ephedrine has anti catabolic characteristics.
Finally, athletes often use Ephedrine as since it has a mild amphetamine-like effect on the central nervous system (CNS). It is important to note that Ephedrine, administered for this purpose, is not to be taken regularly otherwise, the body gets accustomed to it and the effect decreases, and much higher dosages are needed.

Side effects can manifest themselves in the form of more rapid heart beat, insomnia, tremors (light trembling of the fingers), headaches, dizziness, high blood pressure, and lack of appetite. The last characteristic, however, is much appreciated by athletes on a diet. Ephedrine must not be taken when high blood pressure, a severe hyperfunction of the thyroid gland, irregular heart rhythm, or a recent myocardiac infarction are present. In Europe Ephedrine is a prescription drug which is mostly available in combination with other substances. Such a combination compound, for example, is the German drug Perspiran N, which contain an additional 25 mg Ephedrine hydrochioride and 125 mg tlieopriyiline per tablet. Ephedrine as mentioned in the above posts is in many decongesgants aswel such as lemsip!

Hope this helps.