Silver colloidal or colloidal silver is made up of tiny particles of silver in a suspension. In this, it is much like colloidal gold. Like gold, silver does not serve an essential function in the body, but people take colloidal silver to support their immune system and as an anti-bacterial and anti-viral. Before modern antibiotics were developed, colloidal silver was used as an all-purpose remedy for many infections and illnesses. Those that used colloidal silver would use as a dietary supplement or apply it directly to the skin.