Most cough syrups have alcohol bases. The definition of the word "elixir":
1. Pharmacology . a sweetened, aromatic solution of alcohol and water containing, or used as a vehicle for, medicinal substances.
Nyquil is 50 proof....
OP - I've had this nasty cold for going on 2 weeks now, too. It started in my head and worked through my throat to my lungs, where it's camped out since. I do not usually get sick from colds (I took care of that in grade school by getting one every week). This one has really hung on, and made me miserable. Really mucous-y and I've been producing phlegm like a heroin addict. It's terrible. The good news is that I think I'm out of the woods, but it took almost 2 weeks to get here. This was gifted to me by a coworker, who promptly gave it to about 10 others...ugh