Knew a guy who would take 15 in one night while going out drinking. I also witnesses a guy take 48 at one time. Saw him counting out these pills in the parking lot and didn't really pay too much attention to it and then he came over to use a another guy asked what he just took. I can take a half of one and my hair feels like it's sticking straight up.
When they first came out back in 92 or so, you could get them for 25$ for 1000, 25 mg. pills of pure ephedrine. I remember at college I bought a bottle and me and my roommates took 30 a piece cuz we had no clue how strong they were. We went out, had no problems, at least not me. Anyway, I drank a lot, went home with some chick, could not perform whatsoever and came back home at about 5 in the morning where my buddies were just sitting on the couch watching TV. They were like "what the fuck did you give us? We can't fkn sleep!" I tried to dose off, but that wasn't an option, I wound up joining them playing NBA JAM all night. We took a lot less after that.