Can you prevent or stop a common cold just with copper? Usually when an article asks an upfront question like that the answer is no. In this case the answer is – maybe, well, it’s complicated. The seller of CopperZap would like you to think that it does, however. On their website they proclaim, “New research indicates you can stop a cold naturally before it starts.” The site is also loaded with anecdotes, such as, “Seven years without a cold. – Inventor Dr. Doug Cornell, PhD.

What did Dr. Doug invent? A chunk of copper. It is shaped into a convenient wand that can nicely fit up your nose, which is the intended function. For this convenience he charges $69.95, for what looks like less than $1 worth of copper (currently $2.65 per pound). Can simple copper prevent a cold? It certainly sounds like a classic crank medical device, like copper bracelets and magnetic wraps. But there is some actual science behind these claims, just insufficient to justify the specific claims being made.

There are various kinds of medical pseudoscience we encounter. Sometimes the alleged intervention is spiritual in nature, or it is basically some kind of magic (or might as well be). Homeopathy, for example, is essentially witchcraft, with magic potions that have zero basis in reality. But a lot of modern snake oil is based on some science. This is extremely useful for marketing, because you can cite the relevant science and pretend to be all legitimate. What makes such products snake oil is that they are making claims that go well beyond the existing science. Typically this amounts to taking basic science or pre-clinical evidence and then skipping over decades of clinical research to make specific unsupported clinical claims.

This can superficially seem reasonable, especially to those without medical expertise, but even many experts who should know better fall for this fallacy. If, for example, a certain substance increases a marker of immune activity in a petri dish, it seems reasonable to extrapolate to the hypothesis that it may increase immune activity in an organism and help fight infections or cancer.

However, such simplistic (if compelling) extrapolations have a very poor track record. In one review, only 1% of such basic science mechanisms led to a treatment even decades later. The problem is – there is a lot that can go wrong when leaping from the petri dish to the clinic. First, markers are just that – markers. They are something we can measure that we think indicates an underlying process, which is what we are really interested in. But markers may not indicate what we think. They may be a byproduct, and not the process itself.

But even if we are measuring something useful more directly, like killing cancer cells or viruses, a petri dish is not a full biological organism. Creatures are complex dynamic homeostatic systems. These systems are not easily manipulated in a positive way, and it is horrifically complex to predict the net effect of any intervention in a living system. You have to study the effect itself to really know.

There are also some practical limitations, one being bioavailability. If you are dripping a substance directly onto cells in culture that does not predict what will happen when you eat the same substance. Will it get absorbed, will it go to the part of the body where it is needed, in what concentration, and will it be inactivated in some way along the way? There are all points of potential failure.

Also, are there any unintended negative effects? What is the balance of benefit to side effects? What is the dose-response curve of benefit vs toxicity? What about long-term effects, or interactions with other interventions or disease states?

This is where clinical research comes in. Ideally we should have some reason to think that an intervention will have a specific positive effect, either from basic science or clinical observation. Then we conduct carefully designed rigorous clinical trials to evaluate all the questions above. Again – only a tiny portion of good ideas make it all the way through this clinical gauntlet to become a useful medical treatment.

Or – you can take a basic science or anecdotal observation, skip over the clinical research that would be necessary to know if it actually works, and go straight to marketing. That is apparently what Dr. Doug did (by the way, that PhD is in social psychology).

So what does the science at this point actually say? The basic claim that metallic copper kills viruses (and bacteria) on contact is actually true. There are now several studies indicating that copper is a “contact killer” of many microorganisms and potential pathogens. It seems that copper ions released from the surface create powerful oxygen free radicals will destroy cell membranes and DNA. Copper can bind proteins and inactivate them, and interfere with nutrients.

Alloys of copper are also effective, but it appears that the more pure the copper the more quickly it kills. Zinc has similar but less robust activity. This means that brass, which is a copper zinc alloy, has good antimicrobial activity, which is probably good news for the brass section of the orchestra.

Based on current evidence, in fact, it is reasonable to recommend copper surfaces for high germ areas, like hospitals. It might even be reasonable to have copper covered counters and sinks in your bathroom. But even this more direct extrapolation should be studied – because the final piece to the puzzle when going from basic science to clinical claims is this – is the observed effect clinically relevant? Does it actually help people?

In fact, when studied, having copper surfaces in the hospital does significantly reduce the rate of hospital acquired infections. This evidence is still preliminary, but is sufficient to take it further. As more extensive use of copper in hospitals is used, it should be tracked to measure the real effect size and also monitor for any unintended effects.

What about copper in the home? I could find no data on this. This is not a no-brainer, because copper surfaces may simply be unnecessary in a home setting. It may even have a net negative effect by causing complacency – people may not clean their surfaces as well because they are relying on the copper.

There are also no published studies looking at placing copper in your nose to abort or prevent a cold. This is a huge stretch for a few reasons. One is that the virus may already be too deep in the tissue for copper to work. The studies show that bacteria and viruses sitting right on top of the copper are killed, but this may not apply to viruses in tissue. This is a bioavailability problem.

Also, is the contact area sufficient? How much of the nose membrane do you have to touch, and how deep? What are the dangers of having people put a copper wand deep into their nasal passages? Finally – what duration is sufficient? The evidence does show that germs can die within minutes, but how long will it take in the nose, and how much of the virus or bacteria do you need to kill to make a clinical difference? Will it take five minutes, 10, an hour? Do you have to do each nostril for this time, with how many applications? These are the exact questions a clinical trial could answer.

I always like to hit the “science” tab on websites selling dubious products. In this case, as I would predict, there is a lot of discussion of the basic science (which is not the part that is in doubt). Clinically, there are no published peer-reviewed studies. All they have are in-house studies which are unblinded and therefore anecdotal.
In other words – there is no real clinical evidence. I could not find any in several searches, and it is safe to assume that if such studies existed and were positive they would be prominently featured on the website.

My final assessment is that the copper zapper is another “snake oil” type product with unsupported clinical claims. The basic science is real, however, and the idea is not entirely unreasonable, but we would need to do clinical trials to answer all the practical questions I listed above.
Also – the $69.95 price tag, in my subjective opinion, is a rip-off. It’s a piece of copper. If you want to put copper up your nose in the hopes it will save you from a cold, then go onto Amazon or Etsy and buy a small copper rod for 2-3 dollars.

In one picture on the website they show someone holding the wand against a cold sore. This is even less plausible, as killing any virus on the surface is unlikely to have much effect. But I couldn’t help thinking that you could literally just be holding a penny against the cold sore. There, I just saved you $69.94.


Posted by Steven Novella

Founder and currently Executive Editor of Science-Based Medicine Steven Novella, MD is an academic clinical neurologist at the Yale University School of Medicine. He is also the host and producer of the popular weekly science podcast, The Skeptics’ Guide to the Universe, and the author of the NeuroLogicaBlog, a daily blog that covers news and issues in neuroscience, but also general science, scientific skepticism, philosophy of science, critical thinking, and the intersection of science with the media and society. Dr. Novella also has produced two courses with The Great Courses, and published a book on critical thinking - also called The Skeptics Guide to the Universe.