....Guaifenesin in high doses can cause you to puke your guts out....
Yeah, dude, but what's a "high dose" of guaifensin? Lyserg says it has 100mg per 5 ml. You could safely take 2400mg of guaifensin without even coming close to having any kind of reaction at all. It would take many grams to get sick. And if lyserg is recomending to take 65ml of this cough syrup, that's only 1300mg of guaifenesin. That's like taking a single dose of Mucinex ES. It's nothing.
I wouldn't worry, OP. This cough syrup is what the kids take to get a buzz, and I think that it's what rappers reffer to as "sippin' on sizzer" or some shit, referring to sipping on syrup. It's a joke, and no respectable opiate user considers this a real drug.
I wouldn't worry about taking too much making you sick if you're trying to get a high. Like lyserg said, take 75ml. Or take 100. And if that doesn't work, go up in 50 ml. It might take a while to get a buzz. But I have a very strong feeling that's it's gonna take more like 200 ml to really feel some cool effects.
The idea is to ingest as much codeine as possible, because that's the good stuff. Well, as far as cough syrup goes. But codeine is actually an incredibly weak pain killer. No real pill junkie wants anything to do with codeine cause it's so weak.
And taking a large amount of this cough syrup will cause you to ingest a large amount of psudoephedrine. This is a chemcial that is used in methamphetamine. It is actually an amphetamine, which means it's an upper. It will cause you to be jittery and have a lot of energy. Kind of like if you were to take concentrated doses of redbull, or if you were to take nodoze or something like that.