According to a podcast that seemed like the host knew what he was talking about, you also need the lozenges to not contain any additional ingredients that might make them taste nice, like vitamin C. (If it tastes nice, the zinc isn’t binding in the right place. Bad taste doesn’t mean it’s working, but good taste means it’s not.) As of a few years ago, that brand of lozenge was apparently the only one on the market that would work. More info: https://www.lesswrong.com/posts/un2fgBad4uqqwm9sH/is-this-info-on-zinc-lozenges-accurate
That’s why the peppermint zinc acetate lozenge from Life Extension is the recommended one. So your only other option might be somehow finding unflavored zinc lozenges, which might taste even worse? Not sure where that might be available
Earlier discussion on LW on zinc lozenges effectiveness mentioned that other flavorings which make it taste nice actually prevent the zinc effect.
From this comment by philh (quite a chain of quotes haha):
That’s why the peppermint zinc acetate lozenge from Life Extension is the recommended one. So your only other option might be somehow finding unflavored zinc lozenges, which might taste even worse? Not sure where that might be available