Taking special high-strength zinc lozenges when you have a cold can help you get better about three days faster.
Evidence from Studies
Supporting (2)
Community contributions welcome
Zinc acetate lozenges for treating the common cold: an individual patient data meta-analysis.
The study found that zinc acetate lozenges shorten colds by almost three days, just like the claim says, so it supports the idea.
The effectiveness of high dose zinc acetate lozenges on various common cold symptoms: a meta-analysis
The study found that high-dose zinc lozenges help shorten cold symptoms, which supports the idea that they can reduce how long a cold lasts.
Contradicting (2)
Community contributions welcome
Zinc acetate lozenges for the treatment of the common cold: a randomised controlled trial
This study tested zinc lozenges for colds and found they didn't make people get better faster—in fact, they might have slowed recovery a bit after stopping the lozenges.
Effect of treatment with zinc gluconate or zinc acetate on experimental and natural colds.
The study tested zinc lozenges but found that zinc acetate didn't shorten colds at all, which goes against the claim that it reduces colds by three days.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.