Natural Path / Silver Wings Colloidal Silver is superior in quality and concentration to other products available in the market. The mild silver protein used is chelated to a protein, which keeps it in suspension much more effectively than the electrolysis process. This pure product is a pharmaceutical grade of silver. There are no chemicals used in the process. It is 99.9% silver, with a 19-23% assay, and 0.1% casein. Natural Path / Silver Wings Colloidal Silver is a higher concentration than those supplements sold by the majority of competitors.Colloidal silver from Natural Path/Silver Wings is non addictive and does not have any interactions with other supplements. Colloidal Silver from Natural Path/Silver Wings is the only choice for Physician's Preference because they provide the finest colloidal silver on the market. Shake the bottle well before each use.