What Is the Scientific Evidence for Zinc Nasal Gel and Lozenges?
In a double-blind, placebo-controlled trial, 213 individuals with a newly starting cold used one squirt of zinc gluconate gel or placebo gel in each nostril every 4 hours while awake. 7 The results were significant: treated participants stayed sick an average of 2.3 days, while those receiving placebo were sick for an average of 9 days, a 75% reduction in the duration of symptoms. Somewhat more modest but still significant relative benefits were seen with zinc nasal gel in a double-blind, placebo-controlled study of 80 people with colds. 103 However, a slightly larger study of a similar zinc gluconate nasal gel found no benefit. 113 However, this study has been criticized on the basis of the statistical methods used; 114 in addition, it involved artificial infections with cold viruses rather than a natural cold. A fourth double-blind, placebo-controlled trial, enrolling 185 individuals, also found no benefit with zinc nasal spray. 89 However, this study used a much lower amount of zinc
