Can zinc prevent or shorten the duration of a cold?

Daily preventive zinc intake cannot prevent a cold. Zinc intake during a cold would shorten the duration of the illness, but the studies are of insufficient quality to recommend zinc during a cold.

Some studies show that zinc supplements (such as zinc lozenges or syrup) may shorten the duration of a cold by 1 to 2 days if taken within 24 hours of the first symptoms.

A meta-analysis (Cochrane Review) found that zinc supplementation has little or no effect on preventing colds, but may shorten the duration of colds, but with an increase in non-serious adverse events.

Overall, there was a wide variation in treatments (including concomitant therapy) and outcomes across studies, as well as incomplete reporting of various aspects of the disease and treatment, which hampers conclusions about the effectiveness of zinc in the treatment of colds.

The use of zinc in the prevention and treatment of colds cannot therefore be recommended due to the lack of robust evidence.

Source: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD014914.pub2/full

Author: Prof. Dr. Dirk Devroey - Latest update: 2025-03-03 - Copyright: Clinifacts 2025