Colloidal Silver has been used since the late 1800's in countless applications, and encompasses a wide variety of silver products. Bio-Active Silver Hydrosol represents the ultimate refinement of the colloidal silvercategory. It contains 98% positively charged silver, in pharmaceutical-grade purified water. Sovereign Silver's unprecedented small particle size makes it easy for the body to absorb and excrete. Natural Immunogenics is an NSF certified GMP (Good Manufacturing Process) manufacturer.