Common Cold Remedy May Not be Best

Zinc for the common cold not as effective as its reputation implies

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Zinc is commonly sold as a remedy for the common cold, but whether its effective is controversial. A recent review of research shed some light on this debated treatment.

After examining and comparing the results of 17 trials using zinc to treat the common cold, researchers have concluded that zinc can reduce the duration of the symptoms of the common cold for adults but not for children.

The dose strength and specific form of zinc were factors in how well it reduced symptoms for adults, with high doses of zinc acetate being most effective.

"Try high dose zinc acetate to reduce cold symptoms."

The primary author of this review was Michelle Science, MD, a physician with the Division of Infectious Diseases at the Hospital for Sick Children in Toronto, Ontario, and the Department of Clinical Epidemiology and Biostatistics at McMaster University in Hamilton, Ontario.

In October of 2011, Dr. Science, along with other physician researchers from the Hospital for Sick Children and McMaster University, examined 17 trials using zinc to treat the common cold. There were a total of 2,121 participants ranging from age 1 to 65 in these trials.

All of the trials examined in this review were conducted in developed countries. The goal of this review was to determine the safety and effectiveness of zinc treatment for the common cold.

Some of the trials used placebos, and in these trials neither the researchers nor the participants knew whether zinc or a placebo was used. Other trials simply examined the difference between treatment with zinc and no intervention at all.

There were various forms of zinc used for treatment, including lozenges containing zinc gluconate or zinc acetate, or syrups containing zinc sulfate.

The trials using zinc acetate showed that this formulation of zinc resolved symptoms up to three days sooner than no treatment or placebo. Zinc gluconate only reduced the length of symptoms by slightly less than two days, and zinc sulfate by less than half a day.

Participants treated with zinc in these trials occasionally experienced minor side effects such as minor nausea and a metallic taste in the mouth.

The overall conclusion of Dr. Science and her team is that only the proper form of zinc can effectively decrease the duration of symptoms in adults with the common cold.

However, according to the study authors, the incidence of side effects is strong enough that some people may want to avoid this treatment.

More trials need to be conducted to determine the effectiveness of zinc as a treatment for children with the common cold. At the time of this review, Dr. Science and her team concluded that there was insufficient evidence to suggest it as a treatment for most people.

This was a review and analysis of the current research, which will be published online May 7th in the Canadian Medical Association Journal. There are no reported conflicts of interest. There was no dedicated funding for this research.

Reviewed by: 
Review Date: 
May 6, 2012
Last Updated:
October 11, 2012