Zinc is commonly recognized to shorten the duration of the common cold. Many studies have confirmed this assertion. But, it is important to understand just how helpful zinc really is.
Most of the studies performed have agreed that using zinc products will shorten the duration of the common cold by 1-2 days and will diminish the severity of the symptoms attributed to the common cold by a minimal amount.
So, it is definitely worth considering, but don't expect your cold to fly away with the first lozenge you use,