Zinc-ing Outside the (Tissue) Box: Can Lozenges Help Fight Colds?

In Brief:

Whether you are embarking on a skiing trip, celebrating the holidays, or simply breaking out that ugly sweater, the arrival of winter brings about routines and feelings that most of us can’t imagine the season without. Few things, however, are more routine than catching a cold; adults typically have two to three colds a year, while infants and children can suffer upwards of six colds in the same period of time. Considering that so many people get infected with cold viruses on a regular basis, cold management becomes expensive: annually the purchase of over-the-counter medications and visits to the physician to fight the common cold add up to approximately $40 billion.

While a cure has yet to be found, decades of research into colds have lead to the discovery of a number of viable alternatives. Although most products in pharmacies are designed to alleviate cold symptoms rather than help the body fight the virus, one exception to this rule appears to be the zinc acetate lozenge. Unappetizing as they may be, these little candies may speed up recovery from the common cold.

Dr. Harri Hemilä in the Department of Public Health at the University of Helsinki, Finland, used a statistical approach called meta-analysis to quantify the extent to which zinc acetate lozenges reduce the duration of the common cold. Meta-analyses compile the research carried out by different scientists who design similar experiments and use a combination of statistical models to identify trends and similarities across publications. The compiled research creates a statistical quilt, helping researchers understand the bigger picture. According to Dr. Hemilä, if there are studies that are comparable, scientists can draw better conclusions about the effectiveness of zinc acetate by using what Dr. Hemila calls the “wisdom of the crowd” strategy.

With this approach, Dr. Hemilä and his team have concluded that patients given zinc acetate lozenges recovered from a cold 33% faster than patients who were given placebo lozenges.

What makes zinc acetate lozenges so effective? Interestingly, it is the “lozenge” itself. The chemical bonds in zinc acetate are relatively weak and can break easily. The biological environment in the mouth is sufficient to break up zinc acetate into free zinc ions, which then travel through the body and boost the strength of the immune response to the cold virus. While there is still some ambiguity as to how zinc does this, Dr. Ananda Prasad, a hematologist at Wayne State University, offers valuable insights into the effects that zinc has on a person’s immune response.

Rhinoviruses like the common cold can cause sickness by binding to door-like receptors that protrude from the body’s healthy cells, sneaking into cells and infecting them. When zinc acetate lozenges dissolve in the mouth, large quantities of zinc ions flow into the nasal and oral cavities, two places where rhinoviruses are highly concentrated. The zinc molecules temporarily bind to the “doorways” of healthy cells, thereby blocking viruses from entering and infecting them. When taken frequently (about every three hours while awake), zinc acetate lozenges can protect billions of body cells from infection, resulting in milder cold symptoms and a faster recovery.

The work of researchers like Dr. Hemilä and Dr. Prasad have set a precedent for future investigations into solutions for the common cold. With mounting evidence that the zinc acetate lozenge is an effective treatment for colds rather than a mask to cover the symptoms, continued research into the creation and administration of these lozenges may soon bring a day when the common cold is not so common.


As an epidemiologist, public health specialist, and biochemist, Dr. Harri Hemilä is a researcher for the University of Helsinki, Finland, who studies the effects of zinc acetate and vitamin C on the common cold. He received both his MD and two PhDs at the University of Helsinki. His meta-analysis of common cold patients has successfully quantified the effectiveness of zinc acetate lozenges on human health.

Dr. Ananda S. Prasad has studied the effects of trace elements on human metabolism for over 50 years, making important contributions towards the field of public health. He published several studies on zinc throughout the 1960s, and in 1974 both the Congress and the National Academy of Science declared zinc as an essential element for humans. Now as the director of the Division of Hematology at Wayne State University, Dr. Prasad has published over 300 studies and fifteen books. He is the founder of two scientific journals and is the recipient of numerous distinctions and awards within his field.

Works Cited

  1. Fendrick AM, Monto AS, Nightengale B, Sarnes M. The Economic Burden of Non–Influenza-Related Viral Respiratory Tract Infection in the United States. Arch Intern Med. 2003;163(4):487–494. doi:10.1001/archinte.163.4.487
  2. Hemilä, H., Fitzgerald, J. T., Petrus, E. J., & Prasad, A. (2017). Zinc Acetate Lozenges May Improve the Recovery Rate of Common Cold Patients: An Individual Patient Data Meta-Analysis. Open Forum Infectious Diseases, 4(2), ofx059. http://doi.org/10.1093/ofid/ofx059
  3. Hemilä, Harri “Interview on Zinc Acetate and the Common Cold.” Telephone interview by Sean Oddoye. July 13, 2018.
  4. Prasad, Ananda S. “Interview on Zinc Acetate and the Common Cold.” Telephone interview by Sean Oddoye. August 15, 2018.
  5. Simasek, M., M.D., & Blandino, D. A., M.D. (2007). Treatment of the Common Cold. American Family Physician, 1-2. Retrieved from https://www.aafp.org/afp/2007/0215/p515.html

Image Credits:
Feature Image:

Story Image:

Chief Editor: Akila Saravanan
Creative Team Manager: Lucia Tian
Team Editor: Michael Miller
Team Graphic Designer: Lucia Tian

This article was written by Sean Oddoye. As always, before leaving a response to this article please view our Rules of Conduct. Thanks! -cSw Editorial Staff