As the authors of “Do OTC remedies relieve cough in acute URIs?” noted, half of the clinical trials of zinc lozenges for colds in the last 25 years showed benefit and half did not. Worse, clinical response to zinc lozenges has varied from shortening symptoms by 7 days1 to increasing the duration by 4 to 5 days.2
The enormous difference relates to lozenge formulation.3 Lozenges that release ionic zinc shorten colds and cough in a dose-response manner. Those that don’t release ionic zinc not only do not shorten the duration of symptoms, but may make cough and colds worse.3
I studied the contents of more than 40 zinc lozenges and found that few (or none) release substantial ionic zinc in the sustained manner needed for symptom relief.3 We need a pharmaceutical company to make a zinc lozenge that can shorten cough and colds by a week and take it through the FDA approval process.
George Eby
George Eby Research Institute
Austin, Tex