That’s basically all it is. Rhinoviruses don’t hang with zinc. The vitamin C is probably just to keep you from gagging on the taste.

It’s the quickest way to tell if it’s a cold or some other flu. If Zycam works, it’s some variant of a rhinovirus, and it’ll be dead in a couple days. If it doesn’t work, you’ve made some other viral friend. The other cold like strains don’t seem to give a shit about zinc, so if it’s not immediately obvious it’s working within about 30 minutes, move on to other remedies. If it is working, don’t over do it, you can fuck up your sinuses with too much zinc.