dont do it man.
Studies show pulling all nighters adversly affects memory recall and impedes information comprehension and retention.
Not to mention ephedrine slows the brain down. Moral of the story, ephedrine and all nighters dont mix. I mentioned the two together because why else would a person take ephedrine to study.
Anyhow, personal testimonial, I took 5-6 ephedrine tabs prior to a next day exam, and my brain just couldnt comprehend or retain the information. I consequently failed out of college, and am now living as a bum off the street. Jokes.
I highly recommend against taking ephedine as a study aid.