Pseudoephedrine: I'm generally using it to be able to breathe easily since it's a nasal decongestant, so it's often in my system when hiking.
Effedra is the plant from which Effedra leaf tea is made. It contains Ephedrine in a natural form - compared to pseudoephedrine (found in some cold medications, i.e. nasal decongestants, and some diet pills) it has a faster onset (~20min after ingesting), little higher effect/intensity, but around a 40-45 minute duration of effect. Too short of an effect to be used in OTC (no longer off-the-shelf in many [all???] cases) cold medicines, or in some appetite supressing diet pills. Hence, the synthesis of pseudoephedrine in laboratories for medicinal (and diet) purposes. I'm forgetting, but i think it typically peaks around 90min or so after ingesting and has a longer half-life than natural ephedrine, hence longer acting in the body (don't quote me on that 90min figure; i'm really having trouble recalling some things that i used to know "cold" - no pun intended).
I don't think that the FDA took it off the market, they did take if "off the shelves" and behind the Pharmacist's counter though (meth labs supposedly can use large quantites of these pills to make methamphetamines/speed). You now need to sign a registry when purchasing these pills and the day-by-day quantity that you can purchase (at least at any one pharmacy) is limited.
I've used pseudoephedrine (Sudafed and generic brands) for decades, or i generally can't breathe out of one or both nostrils unless i'm working out real hard, then the nostrils clear without the drug.
I would not advise taking mega-doses though in an attempt to improve atheletic performance. This is particularly when things can go wrong with an otherwise healthy athelete - e.g. cerebral bleed, amongst other possible side-effects.
Like i said in my prev. post (see there), it acts on the body in a very natural way - similar to how adrenaline (the fight or flight hormone) acts.
It stimulates the sympathetic nervous system, causing (amongst other effects)...
constriction of capillaries (to reduce bleeding if wounded while fighting or fleeing; this can cause an elevated BP and slight lowering of skin temp; for some medical procedures, a doctor or surgeon may inject epinephrine around the site of an intended incision to reduce bleeding just before the incision is made).
reduction of blood flow to some organs, e.g. the stomach (what animal fighting or fleeing stops to eat) and the gonads (what animal fighting or fleeing for its life stops to reproduce) - this is why it was used in some appetite suppressant diet pills.
in high doses, and in rare instances at normal doses, may cause some "leaking" of urine when sneezing or coughing or after urination (ever hear of someone so scared that they have an accident? adrenaline to blame?)
slight improvement in muscular strength and a reduction in reaction time.
there are other effects also.
It's a banned substance by the IOC (int'l olympic committee). I think it was in '72 or '76 that a US distance swimmer had his Olympic gold medal yanked after he tested positive for this drug which he often used for nasal congestion - it was only recently banned at the time and his coach gave it to him.
In normal doses it has been used for decades by millions of people with little problem. Abuse is another matter, like that very talented 18yr old boxer, whose name escapes me at the moment, who developed a cerebral bleed and died right in front of his father (his coach) and younger brother while doing a heavy bag workout after taking something like 16x, IIRC, the normal dose.
Again, i'm not advocating anyone use pseudoephedrine (w/or w/o caffeine) - only that it works for me in low doses only - haven't tried megadoses so can't comment; anyone should check with your PCP before using it for any purpose, especially if a person is on certain other medications, e.g. sympathomimetic amines amongst others. There are at least a couple of medical doctors who participate in these Forums. Maybe they could comment.