First off, nobody has turned blue from using Silver Sol. This technology has been used for years with no reports of adverse effects. The condition where the skin and gums have a grayish hue is called argyria. It can occur when silver stays in the body at high levels (about 10 times the regular dose of Silver Sol) for a long time (think decades). Users of ionic and colloidal silver preparations can have too high concentrations of silver and could possibly develop the condition. However, research suggests that 98% of the Silver Sol leaves the body by the next day, so there is no need to worry about argyria.