Zinc inhibits the reproduction of rhinovirus, and has been found to be especially good for treating viral sore throats. A recent study on the effectiveness of zinc showed that taking a zinc lozenge every 2-3 hours, shortened the duration of cold symptoms. Overdosing with zinc can have side effects, such as an effect on the uptake of iron.
Dosage: one lozenge every 2-3 hours for duration of the cold or flu. Keep in the mouth for 5-10 minutes. Or 30 to 50 milligrams a day.