Most Zinc Lozenges Don't Work, But the Right Ones Can Cut Your Cold by 3 Days
The best zinc lozenge trials show something genuinely impressive: colds shortened by roughly 40%, with triple the chance of being recovered by day five. That translates to about three fewer days of misery from a typical week-long cold. But here's the catch. Many of the zinc lozenges you'll find at the pharmacy are either under-dosed, formulated with ingredients that neutralize the zinc, or both. The difference between a lozenge that works and one that's dead on arrival comes down to details most people never check. A 2024 Cochrane review of 19 treatment trials found zinc may shorten colds by about 2.4 days on average, though the evidence was graded low-certainty with high variability between studies. That variability isn't random. It maps closely onto differences in dose, formulation, and how the lozenges were used.