A meta-analysis of zinc salts lozenges and the common cold

Arch Intern Med. 1997 Nov 10;157(20):2373-6.


Background: In the United States, the common cold has been estimated to cost more than $3.5 billion a year. Despite several randomized clinical trials, the effect of treating colds with zinc salts lozenges remains uncertain because of conflicting results.

Objective: To conduct a meta-analysis of published randomized clinical trials on the use of zinc salts lozenges in colds using a random effects model.

Results: Eight clinical trials of treating adults with zinc salts lozenges were identified. After excluding 2 studies that used nasal inoculation of rhinovirus, 6 trials were combined and analyzed. The summary odds ratio for the presence of any cold symptoms at 7 days was 0.50 (95% confidence interval, 0.19-1.29).

Conclusion: Despite numerous randomized trials, the evidence for effectiveness of zinc salts lozenges in reducing the duration of common colds is still lacking.

Publication types

  • Meta-Analysis

MeSH terms

  • Administration, Oral
  • Adult
  • Common Cold / prevention & control*
  • Common Cold / virology
  • Double-Blind Method
  • Humans
  • Incidence
  • Odds Ratio
  • Randomized Controlled Trials as Topic
  • Reproducibility of Results
  • Treatment Outcome
  • Zinc / therapeutic use*


  • Zinc