A previous meta-analysis found that high dose zinc acetate lozenges reduced the duration of common colds by 42% – According to the calculations by Hemilä and Chalker, high dose zinc acetate lozenges shortened the duration of nasal discharge by 34%, nasal congestion by 37%, sneezing by 22%, scratchy throat by 33%, sore throat by 18%, hoarseness by 43%, and cough by 46%. Furthermore, they found strong evidence that zinc lozenges also shortened the duration of muscle ache by 54%.
* The effectiveness of high dose zinc acetate lozenges on various common cold symptoms: a meta-analysis BMC Family Practice 2015, 16:24 doi:10.1186/s12875-015-0237-6