The guaf is just an expectorant (makes it easier to hack phlegm up), the ephedrine is the decongestant.
I cant see a problem with you taking it 4 times a day. The guaf may make you a bit nauseous, though.
With 5 weeks to lose 5 pounds, why not just go on a mild diet? Shit, you could lose 10 pounds in 5 weeks without any ephedrine.