What Is Colloidal Silver? Colloidal silver refers to a liquid that contains small silver particles suspended in it. While it is often marketed online as a supplement, there is no substantial scientific support for the health claims made about its use. Is Colloidal Silver Safe? The U.S. Food and Drug Administration (FDA) maintains that colloidal silver is neither safe nor proven effective in treating any medical condition. In fact, both the FDA and the Federal Trade Commission have taken