Colloidal Silver | Silver Colloids

Testing for Silver Protein

To find out whether you have a silver protein product rather than a true silver colloid, look for these characteristics:

  • Makes foam: When shaken, a silver protein product produces foam above the liquid that will persist for minutes after being shaken. This is probably the single most reliable indicator. Even when the product label identifies the product simply as colloidal silver and never mentions the word protein, this indicator will signal the presence of a protein binder. Shake the bottle and look for foaming. When the foam persists, protein is present.
  • Concentration:   Silver protein products tend to have very high concentration values, typically in the range of 30 to 20,000 ppm. Concentration is expressed in parts per million (ppm) and is numerically the same as milligrams of silver per liter of water (mg/L).
  • Color: The color ranges from light amber to almost black with an increasing concentration of silver.


  • Due to the high concentration of large silver particles, silver protein products are known to cause argyria, a condition that causes the skin to turn blue-gray. These and other dangers associated with silver protein are described in About Silver Protein Products.
  • Adding protein to colloidal silver is also potentially unsafe because of bacteria, according to Professor Ronald Gibbs who discussed this fact in his booklet “Silver Colloids“. He found “mild silver protein” products that had live bacteria growing on the protein. This can happen when protein is mixed with colloidal silver because the protein molecules are large and encapsulate the silver particles, which prevent the silver from reaching the bacteria to kill it. Normally, it would be impossible for bacteria to live in colloidal silver, but it is common in products containing protein. For this reason, Professor Gibbs recommended that silver protein products should be avoided. Here is the quote from Professor Gibbs book concerning use of protein to stabilize colloidal silver: “A fifth sample considered showed fuzzy clusters around silver particles when viewed in water . . . . As suspected, this fuzzy material fluoresced indicating the material was, indeed, live bacteria growing on the gelatin that had apparently been used to stabilize the colloidal silver suspension. In Figure 3A the black dots inside the fuzzy mass are the silver particles. This sample exhibits the poor quality control that is totally unacceptable in this type of product. This sample was removed from further consideration and analysis .” Professor Gibbs’ book “Silver Colloids, Do They Work?” can be downloaded here.


List of Silver Protein-Based Products

Click here for a partial list of silver protein-based products by brand name.

Related Information

True colloidal silver products are the least prevalent type of colloidal silver on the market due to high degree of manufacturing complexity and the resulting high cost of production.

In true colloidal silver, the majority of the silver content is in the form of silver particles. True colloids will typically contain more than 50% particles (often 50 – 80%), while the balance (20% to 49%) will be silver ions. When referring to colloidal silver, the word colloid means silver particles.

The two critical factors to look for in determining true colloids are the percentage of silver particles and the particle surface area.  

Of all the types of silver marketed as colloidal, true colloidal silver products have the highest particle surface area. High particle surface area is achieved by a high percentage of silver particles combined with very small sized particles. Of the three types of silver on the market, true silver colloids have the highest particle surface area relative to the total silver content. The ratio of particle surface area to total silver content indicates how efficiently the colloid is able to produce particle surface area which determines effectiveness. Higher conversion efficiencies are more desirable.

The nanometer-sized particles in true silver colloids remain in colloidal suspension without requiring protein or other additives. It is the mutual repulsion of the particles created by the zeta potential charge that keeps the particles uniformly distributed in the colloid.

Determining True Silver Colloids

Because of the high concentration of silver particles, true silver colloids are never clear like water. True colloidal silver with a sufficient concentration of particles does not look like water because silver particles — even very small particles — block light from passing through, making the liquid appear darker.


Due to the very low concentration of ionic silver and small particle size, true silver colloids do not cause argyria, a condition that causes the skin to turn blue-gray.  

List of True Colloidal Silver Products

Click here for a partial list of true silver colloid products by brand name.


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