Don’t count on zinc acetate lozenges to quell a cold: A study in BMJ Open found that they did not shorten cold duration in 45 people who started taking this popular over-the-counter remedy right after symptoms came on (78 milligrams of elemental zinc per day for five days), compared to a placebo given to 42 other cold sufferers.
While lab studies have shown that high doses of zinc can block cold viruses from adhering to the nasal lining and replicating, clinical trials have had inconsistent results, perhaps due to different zinc formulations, doses, and regimens tested.
If you decide to still try zinc lozenges for a cold, begin as soon as possible, following the dosing directions on the label. The lozenges can cause stomach upset and a bad taste in the mouth. There is no evidence that taking zinc long-term prevents colds.
