Medical uses of silver: history, myths and scientific evidence

Silver has no biological role and it is particularly toxic to lower organisms. Although several silver formulations employed in medicine in the past century are prescribed and sold to treat certain medical conditions, most of the compounds, including those showing outstanding properties as antimicrobial or anticancer agents, are still in early stages of assessment, that is, in vitro studies, and may not make it to clinical trials. Unlike other heavy metals, there is no evidence that silver is a cumulative poison, but its levels can build up in the body tissues after prolonged exposure leading to undesired effects. In this review, we deal with the journey of silver in medicine going from the alternative or Do-It-Yourself drug to scientific evidences related to its uses. The many controversies push scientists to move towards a more comprehensive understanding of the mechanisms involved.