The concept of zinc preventing and alleviating cold symptoms is not a new one. Zinc lozenges, zinc tablets, and the popular product Zicam - in all it's delivery methods - have been around for quite a while. While they are definitely effective, most supplements and zinc consumption modalities have failed to address of the issues of Zinc's status as a positively charged ion.
Adding an ionophore of zinc to the equation gained more widespread attention during the early portion of the Cov-19 outbreak, and was more widely tested against existing pharmaceuticals that worked as zinc ionophores. Below are some one minute snips of a medical lecture; the first covering the action of zinc in the cell and the need for an ionophore for access to the cell, the second showing scans of intracellular zinc concentrations with and without an ionophore.
At the time, there was a lot of protest about the safety of the pharmaceutical ionophores available, namely chloroquine and hydroxychloroquine, despite their long track record of efficacy and safety, especially in regard to the latter. As such, many doctors were not allowed to prescribe the medications. Fortunately for doctors, and everyone else, there are some very strong zinc ionophores that exist in natural supplements. One of the strongest ionophores, and a great stand alone supplement, quercetin, fits the bill perfectly and is available over the counter.