Zinc Lozenges Reduce Common Cold Symptoms


Zinc Lozenges Reduce Common Cold Symptoms

New meta analysis shows that using zinc lozenges reduce common cold symptoms.

Treating common colds with zinc to reduce how long you’re sick might sound like an awesome fix, but the science is divided. Previous studies on the area vary, some find an effect reducing length of your illness or severity of the symptoms, while other studies find no effect at all. Is the effect real or simply the result of placebo ? New research from Helsinki University analyze data from three randomized controlled trials and conclude that the data shows that zinc lozenges reduce common cold symptoms.

Zinc Lozenges Reduce Common Cold Symptoms

The common cold is caused by over a hundred viruses and this large number is part of the reason finding a cure is really difficult. “Folk wisdom” recommends a variety of fixes to shorten the duration of colds: chicken soup, hot tea with honey, garlic, or vitamin c. Though some of these tips are supported by scientific evidence, many are just superstitions.

So what about zinc?

The science is divided. One recent meta-analysis concluded that high dose zinc lozenges shortens cold duration by 42%. This data led Harri Hemilä from Helsinki, Finland and Elizabeth Chalker from Sydney to investigate how long  symptoms of common colds persisted, could the duration of cold-symptoms be reduced with high zinc lozenges?

Since lozenges are dissolved in the mouth the expected result would be fewer sore or scratchy throats and smaller, or even nonexistent, effect on respiratory symptoms. However, researcher discovered that this actually wasn’t the case. In some cases zinc lozenges worked even better on respiratory symptoms than on sore and scratchy throats.

In this meta analysis researchers selected three randomized controlled trials testing how zinc lozenges affected cold symptoms in patients receiving between 80 and 92mg of zinc per day. Symptoms of people eating zinc lozenges showed a substantial improvement over those on placebo: lozenges reduced nasal discharge by 34%, nasal congestion by 37% sneezing by 22%, scratchy throat by 33%, soar throat by 18%, hoarseness by 43% and cough by 46%.

In these studies there weren’t any major adverse effects from using zinc lozenges but the FDA warns against using zinc nasal sprays since they could cause a loss of smell.

Zinc lozenges might shorten common cold symptoms but the confidence intervals of the findings, though significant, are very wide. Before more studies confirm the actual effect of zinc lozenges it’s hard to say whether they actually reduce common cold symptoms.

“zinc acetate lozenges releasing zinc ions at doses of about 80 mg/day may be a useful treatment for the common cold, started within 24 hours, for a time period of less than two weeks.” – Lead authors Harri Hemilä and Elizabeth Chalker.


You can read the study here.

Image credit: AJC1 via flickr.com, CC BY-NC-SA 2.0

You can find zinc lozenges on amazon here.