Taking Advantage of the COVID-19 Throat Infection Study With Zinc and Copper [COVID-19 Updates]

On Tuesday, I wrote to you about new study showing that SARS-CoV-2, the coronavirus that causes COVID-19, infects the throat, not just the lungs, and the infection may actually start in the throat before it starts in the lungs. And since the evidence for infecting the throat came from either oropharyngeal swabs (swabs of the mouth and throat) or from nasopharyngeal swabs (swabs of the nose and throat), it may well start in the nose or mouth as well as the throat. When I wrote to you, the paper was a preprint that had yet to be peer reviewed. Yesterday, just one day after I wrote to you, that paper was published in Nature.

Can we leverage this information toward preventing COVID-19?

Although there are no randomized controlled trials of any nutritional supplements in the prevention of COVID-19, I find it worthwhile to speculate. And when something is perfectly safe, and I think it might work, I'm going to take action on it. There's no way I can protect myself from being exposed to the virus 100%, so I will augment hygiene and social distancing with whatever seems to have the best chance of prevention.

Zinc inhibits two of the proteins involved in the replication of SARS-CoV (the 3CL protease and the papain-like protease 2), the coronavirus that causes SARS, and proteins between SARS-CoV and SARS-CoV-2 are on average 87% identical, so it's likely that zinc also inhibits these enzymes in SARS-CoV-2. In fact, these two proteins are known as “cysteine proteases” and their activity depends on the sulfur found in the amino acid cysteine. Zinc inhibits these proteins in SARS-CoV by binding to those sulfurs. Since those sulfurs are essential to the function of cysteine proteases across the board, then it's almost certain that zinc inhibits them in SARS-CoV-2 in exactly the same way.

There's no evidence that zinc is directly toxic to SARS-CoV or SARS-CoV-2. In fact, it probably is not, given that coronavirus 229E survives fine on zinc surfaces. So, zinc probably has little to no ability to kill the virus outside of cells, but enriching our own cells with zinc may well put a stop to the virus being able to replicate within them.

The best way to get zinc into the nose, mouth, and throat tissue is to use zinc acetate lozenges. They have been mainly studied in the context of the common cold (see here, here, and here), where they prevent rhinoviruses from docking to their cellular receptor, ICAM-1. Zinc acetate and zinc gluconate are both effective, but zinc acetate ionizes twice as effectively as zinc gluconate inside the mouth, and the ionization of the zinc allows it to migrate throughout the tissues of the mouth, nose, and throat.

Borrowing from the research on the common cold, I think the best way to enrich the tissues of the mouth, nose, and throat with zinc is to use zinc acetate lozenges at a low dose preventatively, at a more intensive dose when encountering a potential exposure to SARS-CoV-2, and at a dose used in common cold trials at the first sign of illness.

The only zinc lozenges on the market that fulfill all of the criteria to be effective against the common cold are Life Extension Enhanced Zinc Lozenges. They can be ordered now, though they say they are backordered until tomorrow (the site has said this for a month, so hopefully tomorrow they will be ready to ship).

For copper we have a different story. Copper has only been shown to inhibit SARS-CoV papain-like protease 2, but it requires almost ten times the concentration of zinc. Copper is probably a very poor inhibitor of viral replication. And yet, copper is extremely toxic to SARS-CoV and coronavirus 229E. This is shown by their inability to survive for longer than five to thirty minutes on copper surfaces, while they survive on most other surfaces for five to nine days. The copper causes oxidative stress, which these viruses have very poor defenses against. In fact, one of the hypotheses for why bats seem to tolerate thousands of coronaviruses without getting sick is that they have very rapid metabolisms and generate high levels of reactive oxygen species. Humans actually use copper to defend themselves from oxidative stress and can tolerate far more oxidative stress than microbes in general (this is why, for example, hydrogen peroxide has so much antimicrobial power, yet pouring some on a wound doesn't completely destroy our tissues).

Since copper surfaces are highly toxic to coronaviruses that have no host cells to actively replicate within, while copper probably isn't a strong inhibitor of viral replication, the main goal with copper for the mouth, nose, and throat should be to safely deliver high concentrations of copper directly to the surface of these tissues during times where we would expect the virus to have recently invaded.

In version 1.0 of the The Food and Supplement Guide for the Coronavirus, I considered it only a minor possibility that SARS-CoV-2 infects the mouth, nose, or throat. I recommended using a fine mist spray bottle to spray ionic copper into the mouth and throat as an optional add-on to the main protocol to get some of the daily copper in that would be needed to balance the high levels of oral zinc.

In a March 18 Twitter discussion, Avi Bitton, MD alerted my attention to the possibility that an ionic copper spray could irritate mucous membranes. In a March 25 verbal discussion published on YouTube, we discussed this further and agreed that copper delivered topically to these tissues would probably only be relevant when supplied very near in time to events of exposure to the virus. Neither of us had any idea what threshold of copper would definitely hurt mucous membranes or how long it might take to cause harm if someone didn't notice any major irritation, but we agreed that someone should pull back if they experience irritation and it should not be used indefinitely.

The best way to deliver topical copper salts to the nose, mouth, and throat without damaging the mucous membranes, in my current estimation, is by using Sterimar Stop and Protect Cold and Sinusitis Relief nasal spray. Sterimar is filtered, preservative-free seawater enriched in copper salts, with eucalyptus and hyaluronic acid. It is formulated to protect the mucous membranes of the nose, and it has been shown to be protective toward these mucous membranes in vitro.

Whereas the ionic copper spray I first recommended has an unpleasant metallic taste, the Sterimar spray pleasantly reminds me of the ocean. I find it can be comfortably sprayed into the nose as directed on the bottle, and can also be sprayed within the mouth.

On March 6, after reading about the toxic effect of copper toward SARS-CoV, I ordered a bottle of Sterimar Stop and Protect Cold and Sinusitis Relief nasal spray. At the time there were only four left, and I wasn't sure whether I would wind up using it yet, but I bought one just in case they sold out. This morning I tested their volume on Amazon and was able to add 500 to my cart. Instead, I ordered three bottles. However, I updated The Food and Supplement Guide for the Coronavirus a few hours ago and Amazon is now sold out. Nevertheless, if you Google the product, there are multiple other online sellers, and a quick sampling of mine shows that there are some available.

My current practice is to take one zinc acetate lozenge per day preventatively. Before and after any deliberate potential exposure event, such as going out in public, or after any accidental exposure event, such as an incorrect use of gloves or masks, forgetting to wash hands before eating, or sticking one's fingers into one's nose or mouth, I will take an extra zinc lozenge and use the Sterimar spray in both my nose and in my mouth and throat.

The Food and Supplement Guide for the Coronavirus has now been updated to version 2.0, reflecting my research through today, April 2, 2020. It contains these revisions of the protocol, as well as more detail on how to implement it. Right now I'm able to publish this newsletter on a daily basis because sales of the guide allow me to devote myself to full-time research on COVID-19. I am comprehensively reading all the titles of preprints and published papers on COVID-19, stopping to read abstracts or full papers where I find them likely to have practical relevance, as well as keyword searching intensively for specific topics I will comprehensively review on this list, such as ACE2 and the mechanisms of the cytokine storm. If you would like to purchase a copy of the guide, you will help make it possible for me to continue doing this research, and I will be very grateful for that.

Please Support This Service

These research updates are made possible by purchases of The Food and Supplement Guide to the Coronavirus. The guide contains my most up-to-date conclusions about what we should be doing for nutritional and herbal support on top of hygiene and social distancing for added protection. Due to the absence of randomized controlled trials testing nutritional or herbal prevention, these are my best guesses for what is likely to work without significant risk of harm, based on the existing science. Purchasing the guide is also a way to donate $9.99 toward this service of providing free research updates, as the financial support provided by the guide is what enables me to spend time staying on top of the research.


I am not a medical doctor and this is not medical advice. I have a PhD in Nutritional Sciences and my expertise is in conducting and interpreting research related to my field. Please consult your physician before doing anything for prevention or treatment of COVID-19, and please seek the help of a physician immediately if you believe you may have COVID-19.


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