Zinc lozenges may shorten the life of the common cold by as much as 40 per cent, researchers have discovered - but they are effective only if you allow them to dissolve slowly on the tongue. People who swallow the lozenges quickly seem to get little if any benefit.
Researchers from the University of Helsinki in Finland analysed 13 previous trials that have been carried out on zinc lozenges. Those that used lozenges with 75 mg of zinc were the most effective, and reduced the duration of a cold by up to 42 per cent.
The only side effect was a bad taste in the mouth afterwards.
(Source: Open Respiratory Medicine Journal, 2011; 5: 51).