Common ColdZinc

Effect of the dose of zinc lozenges on the common cold

Researchers at the University of Helsinki, in Finland, examined whether the total daily dose of zinc might explain part of the variation in the results of previous studies.

First, the details.

  • 13 comparisons of zinc lozenges to placebo on common cold episodes were reviewed.
  • Emphasis was placed on the dose response to zinc.

And, the results.

  • Total daily zinc dose less than 75 mg: uniformly found no effect.
  • Zinc acetate daily dose over 75 mg: 42% reduction in the duration of colds.
  • Zinc salts (other than acetate) daily doses over 75 mg: 20% reduction in the duration of colds.

The bottom line?

The authors concluded, “Benefit is observed with high doses of zinc but not with low doses.”

Based on these findings, the daily dose of zinc should be greater than 75 mg per day. The authors recommend, “The effects of zinc lozenges should be further studied to determine the optimal lozenge compositions and treatment strategies.”

8/3/11 20:13 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.