Richard Stead, CEO of Qures Group, discusses the century-long history of Hypothiocyanite and the Lactoperoxidase System, and their modern potential in the fight against AMR. In late 2012, I set out deliberately to understand how nature protects the body at its most vulnerable entry points. I was searching, without knowing the name, for a natural antimicrobial molecule capable of preventing pathogens from entering through the eyes and mouth. These sites are moist, nutrient-rich, and constantly exposed to the environment, yet infections there are surprisingly rare. Something must be working with a competence comparable to that of the skin. What I eventually found was Hypothiocyanite (OSCN⁻), a molecule I had never encountered before. To my surprise, it had already been described a century earlier. Its biology and chemistry had been mapped decades before I began my search, yet its relevance, power, and potential remain profoundly under-recognised. This article provides a concise historical overview of the discovery of Hypothiocyanite and the Lactoperoxidase System (LPS), explaining why this natural defence mechanism is so critical in an era of rising antimicrobial …