I'm sorry a lot of what has been said on this thread is, well from a chemist/biochemist's point of view quite incorrect.
Mona is right, pseudoephedrine is "speed" for the body. It cannot and will not get into the brain and hence has little effect on ones central nervous system. If it did then it would be speed, and well i don't think it'd be in just about EVERY cold/flu/sinus medicine in the world, if it was.
Take lots and u'll feel kinda jumpy, anxious, heart will go crazy etc. Generally its natural if ur body is rushing, ur mind will follow it to a degree, but its psychological.
Now EPHEDRINE on the other hand is a better stimulant. U won't find that stuff here, banned a while ago i think, although popped up in herbal ecstasy etc. this is what the truckies get/got stuck into. A greater amount gets into the brain and has quite a good stimulant effect, but again nothing like meth/speed.
The sudafeds aren't being changed coz of abuse.
Meth cooks use pseudoephedrine to make methamphetamine as stated. The changed formula is i think something to do with the binder. The action of the drug in the body is unchanged, but the binder is a bitch for the cooks to work with.
Alcohol will not make the pseudo speedier. (i'm baffled as to where this came from, unless u get so off ur face and "think" ur speeding, then ur next drink will put u on ur arse, and when u wake up u won't remember what it felt like anyway)
Pseudoephedrine hydrochloride is the same as pseudoephedrine for our purposes. When u have MDMA ur most likely having MDMA-hydrochloride. Its just the drugs in crystalline/powder form.
And finally with regards to one of the posts above: ephedrine/pseudoephedrine has NOTHING to do with ecstasy (MDMA not herbal) whatsoever. Ephedrine and meth are structurally related.
But Sudafed does not release serotonin on its own and in no way is used in making MDMA. MDMA and pseudoephedrine really shouldn't be in the same sentence.
God if whats been said is true i feel a cold coming on right now, gotta go, off to chemist; better get the medic, vicks and chupa-chups while i'm there.