Ephedrine prescription drug
An alkaloid derived from plants in the Ephedra family, Ephedrine is widely used as a stimulant, appetite suppressant, aid to concentration, and decongestant.
Although it is illegal to supply Ephedrine without prescription in the UK, it is not illegal to possess and use personally.
Ephedrine works as a weight loss supplement by speeding up the metabolism, thus increasing the amount of calories you burn. Of course, if your metabolism runs faster the tendency is to eat more, so a drug such as Ephedrine will only actually work if you use it to supplement a sensible plan of healthy eating and regular exercise.
When sold in thermogenic weight loss pills, it is usually part of what is called an ECA - this is a combination of ephedrine, caffeine and aspirin (or alternatively salicin instead of aspirin).
The ECA stack is extensively used by body builders before workouts to provide an energy boost and increase fat burning.
This is a supplement with serious and well documented side effects, which have resulted in its current unavailability in the UK, so you should seriously consider the long term implications before considering taking a drug of this nature.