Little Reason to Encourage Zinc Use for the Common Cold

Zinc for treatment of the common cold was first evaluated in 1984, and results of studies have been mixed ever since. Now, researchers have conducted a literature review to assess these studies’ methodology and data.

Of 105 studies, 14 were randomized, placebo-controlled trials that evaluated the effect of zinc lozenges, nasal sprays, or nasal gels on naturally acquired colds. Only four studies met 11 predetermined criteria for valid experimental design; one found a positive effect of zinc nasal gel on cold symptoms and duration, but the other three found no benefit from zinc lozenges and nasal spray.