Dear Dr. Roach: What do you know about copper killing the cold virus? I’m of the opinion that if it sounds too good to be true, it probably is. Yet, there is a copper product on the market that says it kills the cold virus on contact. Many people have claimed it is effective. Are all these reviews fake? If preventing a cold was this easy, wouldn’t everyone know about it? — J.

Answer: Copper does have antimicrobial properties. Bacteria will die on contact with pure metallic copper. The amount of time needed ranges from a few minutes for some Staphylococcal species to 5-15 days for the bacteria that causes tuberculosis. Viruses, which are somewhere between alive and not alive, being only able to replicate within a cell, can be destroyed by copper as well. For the influenza virus, 99.99% can be destroyed by keeping it in contact with metallic copper for six hours.

Unfortunately, cold viruses and flu viruses can be inhaled and then taken up by cells, allowing them to replicate and further infect a person. There is simply no way a piece of copper can prevent infection by viruses when rubbed on the nose. That’s why there are no clinical trials showing the copper to be effective: It isn’t.

I don’t think most of the people responding are fake. The power of believing that something is working is incredible. I suspect many of the people writing testimonials are also not being exposed often to cold viruses.

There is no way to prevent a cold with 100% certainty.