Funny how you forgot to ask this question Should I use it or not? I would say no. I am not a hypocrite, I have done my share of weed and drug back in college. That is why I am sure to say that if you have any doubts about it, don't do it. Still, you sound like a smart person, you could be the one of those who try it once and never again. DXM is habit forming, no doubt about that. As for side effect, there are many, complications you could die, effects ask your friends, they can explain it the best!
It does in my case. Feeling of nausea lasts for about an hour, sometimes less, but it is there. Sometimes I have an urge to puke, but nothing gets out. After that, bliss comes. I cannot say what to do for that starting nausea feeling, but I am used to it now, I just survive that hour and then I am out of there! Literally. I don't know, if you cannot coupe with that nausea, just switch to something else.