MesoSilver is .9999 pure silver nanoparticles in colloid form, a TRUE colloidal silver, which means predominantly silver particles NOT silver ions. The world\'s highest particle surface area. Up to 600 times greater than other products. Highest bioavailability of any colloidal silver product, due to sub nanometer sized particles. World\'s smallest silver nanoparticles, typically less than 1 nm. It is an all natural mineral supplement. Colloidal silver made with the highest purity, sterile reagent grade deionized water, with no potentially dangerous protein products. Mesosilver will not cause Argyria, a discoloration of the skin caused by silver protein products. Colloidal silver does not require refrigeration after opening. Infinite shelf life. MesoSilver is non toxic (per Material Data Safety Sheets). NOTE: high PPM (parts per million) does NOT necessarily mean high PSA or bioavailability. Colloidal silver concentration is 20 ppm minimum. Please see our web site purestcolloids or our company information here on amazon for more technical information on colloidal silver and the pitfalls of some other products. It is very important to read and understand why our product is different then competing products. MesoSilver is a registered trademark of Purest Colloids, Inc.