I was making rounds at the hospital and, for some strange reason, I was being asked about influenza. No, this is not going to be an entry on influenza. But I was asked if there was anything besides the vaccines that can prevent influenza.  Masks and good hand washing will help, I said.

Anything else?

A nurse suggested colloidal silver.

I said there was nothing to colloidal silver.  With what I would describe as a withering look, she opined that not only had she never had the flu because she took colloidal silver, but that she has a friend whose tumor has been in remission for 6 years because of colloidal silver.  She had to respond to an alarm and I had to move on to the next patient, so we yet had an opportunity to converse further on the topic. Which is good because it occurred to be I did not know much about colloidal silver beyond the fact it can turn you blue.  So this entry in my attempt to prepare for my next discussion with a colloidal silver proponent.

Silver is an antiseptic, not an antibiotic.  It has the advantage of most antiseptics in that organisms do not easily  become resistant. It does kill a large number of pathogens and is used clinically.  Silver is impregnated into catheters to prevent infections.  Silver nitrate has been put in the eyes of newborns to prevent gonorrhea.

Various formulations of silver have been tried to aid wound healing, with little effect and Silvadene, silver sulfadiazine, has long been used to treat burns, although its efficacy, when compared to everything from honey to aloe, is often found wanting.  So there is variable clinical data to perhaps supporting use of some forms of silver to treat or prevent some infections.  I will admit to an affinity to suggesting honey and or sugar for chronic wounds; that should be a topic for another post. There are also uses of silver for water purification. So there are legitimate reasons to use silver as an antiseptic.

Ancient wisdom is always a guide for therapy. Cupping. Bleeding. Purging.  Popular therapies back in the day. Silver containers was used by ancients to keep water and other fluids fresh. I cannot find independent verification of this fact, perhaps they kept water in silver because silver is pretty and rare and good for demonstrating wealth, and we are attributing its antiseptic properties retroactively.  Nor can I find independent verification that Royals were called blue bloods due to chronic silver exposure from their eating utensils.  Odd that colloidal silver sites would mention this, since it is evidence of toxicities they deny occurs in other sections of the same websites.  The use of apocryphal information appears to be standard in the colloidal silver ‘literature’.  It is rare to have so little verifiable information about a treatment.

As I have discussed before, users of alternative therapies are not comfortable with nuance and subtlety, and,  I think, prefer black and white binary approaches.  Mercury in one form is toxic, so all forms of mercury are toxic.  Some forms of silver are beneficial, so all forms of silver of benefit, including colloidal silver. The inability to deal with shades of gray is a hallmark of many forms of alternative therapy.

As best I can tell, silver was used as a medicine for years by grinding it up and suspending it in water.  The problem is that the silver is not dissolved but is a suspension and it rapidly settles out of solution. What people were looking for at the turn of the century was a way to keep the silver in suspension. Colloids occur when one substance is evenly distributed in another without being dissolved, like antibodies or albumin in blood.  Or fat in milk.  Proteins like albumin have the advantage of binding metals like silver and allow them to stay in suspension for long periods of time.

“The broader commercial definition of “colloidal silver” includes products that contain various concentrations of ionic silver, silver colloids, ionic silver compounds or bound proteins in purified water. Colloidal silver with concentrations of 30 parts per million (ppm) or less are typically manufactured using an electrolysis process, whereas colloidal silver  with higher concentrations of 50 ppm or more are usually silver compounds that have been bound with a protein.”

In the form of colloidal silver it is ingested for various alleged  health benefits, especially to treat infections.

How many infections?  “Colloidal Silver safely kills over 650 disease-causing bacteria, viruses, fungi, parasites, and molds, has no negative side-effects.” 650! Wow! Where does that number come from?  It, evidently was pulled out of thin air in a 1976 Science Digest article entitled “Our mightiest germ fighter
which was a discussion of of of not colloidal silver, but silver sulfadiazine, aka silvadene and other topical uses of silver.

And nowhere in the article is 650 validated. It was a number that appears to have been invented by the headline writer.  Not that Science Digest is peer reviewed journal and has to reference their headline. But that 650 has taken on a life of its own.  Like 98.6 being normal body temperature.  Many of the colloidal silver sites trumpet this on their websites (43,000 Google hits for “Colloidal Silver kills over 650″ as a search term.”  650 is so sciency, even if made up.

Could silver kill 650 various and sundry organisms?  I would not be surprised if it were the right concentration.  Silver is toxic to cells, so it should kill germs. And it does. Like mercury or gold.  In its elemental form they are toxic and will kill living things at the right concentration.  As will isopropal alcohol; ingestion may not be such a good idea. Many chemicals can kill a wide variety of bacteria in the test tube.  The question is whether they have the same effects in humans and or animals.

If you look on Pubmed for the antimicrobial effects of colloidal silver, I find nothing. No test tube studies, no animal models, no case reports, no clinical trials. As far as the medical industrial complex is concerned there is, outside of toxicities, no supporting data of any kind for the use of colloidal silver.  The interwebs does allow access to susceptibility tests of colloidal silver that are published by the companies that make colloidal silver products.  However,  conflict of interest is not part of the alt med world, so we do not need to worry about their validity.  Sarcasm aside, the studies are growth of bacteria in various concentrations of colloidal silver products and as the concentrations increase, the bacteria die more rapidly.  That’s the usual dose-effect of a poison. They also tout that bacteria can’t become resistant to silver. Always a mistake, for to misquote the Borg, resistance is inevitable as E. coli has demonstrated.

So there is no data to support silver to treat infections.  What about cancer?  It is suggested, with often identical wording on website after website, that  “Dr. Bjorn Nordstrom, of the Karolinska Institute, Sweden, has used Silver in his cancer cure method, for many years. This brought rapid remission in patients given up on by other doctors.”  I do not know who was first with this sentence so I am uncertain whom to credit with the first use of this phrase.

But here is the weird thing.  Although Dr. Nordstom is credited with the same breakthrough with exactly the same sentence in site after site, I can find no English language reference that confirms there is a Bjorn Nordstrom or any details as to how he uses silver for a cancer cure.  Dr Nordstum has not published on Pubmed.  The only reference on the interwebs to a Dr Nordstom is in Swedish. If someone can translate we may find out more. The Swedish word for silver, silvret, is not on the page. I suspect, from reading the Swedish, he may be married to Betty Crocker.

So for what diseases is there evidence for which colloidal silver is  efficacious? Well, nothing.  Pubmed is silent on taking colloidal silver to benefit any disease, infection or otherwise. There are no clinical trials to show efficacy. Nothing.

There is, however,  little to suspect that colloidal silver, taken orally, would be of benefit.  There are not even basic pharmacokinetic studies to show how much of a given colloidal silver preparation is absorbed. Nothing. We know it is absorbed, as there are multiple cases of argyria reported in the literature. Argyria is where the silver gets irreversibly into the skin and you turn not silver but blue or blue gray.  It is an unusual side effect, but the only documented effect of prolonged ingestion colloidal silver.

If you Google colloidal silver, you will find multiple sites where you can purchase various formulations of colloidal silver with variable concentrations of silver.  All of the purveyors of these substances agree that theirs is the one true formulation for silver and that the others are flawed with the wrong size of silver molecule or the wrong preparation.  Which one is truly the true silver colloid? All. Or none I would suppose.

One seller (many of these people really need a web designer) sells increasing concentrations of colloidal sliver, with the higher  concentrations for the most cost (1500 dollars for 6 bottles) to treat ” Severe Infections and Life and Death Infections Ebola, Dengue Fever, Malaria, SARS, West Nile  at a dose of 1-3 tablespoon (15-45 cc) every 4 hours”.

There appears to be as many silver formulations as there are silver sellers, and if you are a do it yourself kind of person, you can make your own colloidal silver.

What perpetuates the use of colloidal silver are testimonials, like the nurse who suggested silver to prevent H1N1. The interwebs are filled with unsubstantiated testimonials, for common infections and unusual infections, with one gentleman crediting colloidal silver, rather than the vancomycin and gentamyin,  for the cure of his subdural empyema (pus between the brain and skull).

The FDA, with little effect to judge from the interwebs, has declared that colloidal silver is neither safe nor effective and, as an unclassified drug, cannot be sold for medical reasons.

Even the National Center for Complementary and Alternative Medicine, who rarely finds anything alternative therapy without some caveat to support its use, says.:

“* Silver has no known function in the body

* Silver is not an essential mineral supplement or a cure-all and should not be promoted as such

* Claims that there can be a “deficiency” of silver in the body and that such a deficiency can lead to disease are unfounded

* Claims made about the effectiveness of colloidal silver products for numerous diseases are unsupported scientifically

* Colloidal silver products can have serious side effects

* Laboratory analysis has shown that the amounts of silver in supplements vary greatly, which can pose risks to the consumer.”

Of course, this review leaves me with blanks in my SBM gun.  I have no data to say there is no reason to use colloidal silver.  To combat the testimonials I have, well, nothing.  No science and no substance.  It is the Oakland of alternative medicine.  Except for toxicity, all the supporting data I can find,  history, 650 germs killed, Dr. Bjorn Nordstrom, the testimonials, and the formulations of colloidal silver are based on unverifiable information or apparently made up.  It is a house of silver cards.  However, if the Blue Man Group is looking for members, I know a potential source that will save on makeup costs.



  • Mark Crislip, MD has been a practicing Infectious Disease specialist in Portland, Oregon, from 1990 to 2023. He has been voted a US News and World Report best US doctor, best ID doctor in Portland Magazine multiple times, has multiple teaching awards and, most importantly,  the ‘Attending Most Likely To Tell It Like It Is’ by the medical residents at his hospital. His multi-media empire can be found at

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Posted by Mark Crislip

Mark Crislip, MD has been a practicing Infectious Disease specialist in Portland, Oregon, from 1990 to 2023. He has been voted a US News and World Report best US doctor, best ID doctor in Portland Magazine multiple times, has multiple teaching awards and, most importantly,  the ‘Attending Most Likely To Tell It Like It Is’ by the medical residents at his hospital. His multi-media empire can be found at