Just look for Robitussin or any store-brand version (Wal-tussin, CVS-tussin, whatever) and look at the ingredients before you buy it and MAKE ABSOLUTELY SURE there is nothing except Dextromethorphan HBr in it. If there is anything else at all, keep looking. I'd say speed is probably worse for you than a regular dose of DXM, but regular doses of either don't really get that bad until they're abused. I'd have to say most people will think speed has a worse comedown than DXM, although while pretty much everyone likes speed (unless they're naturally antsy/anxious), not everyone likes DXM, but if you do like it, it really has more of an afterglow than a crash. I have however heard of allergic reactions to DXM, and not speed, so have your friend start low. Of course, you could just be a freak like me, and get an afterglow even from speed. I enjoy deliriants so a speed comedown feels more like a pleasently weird state of mind to me.