Despite enormous progress in understanding COVID-19, there is little evidence that a
solution, therapeutic or preventive, is close to being achieved. Repurposing of well known,
widely available drugs represent an attractive approach to speed up availability of active
treatments. Such substances as i.e. hydroxychloroquine and others, are already under
investigation and in widespread off label use. For many reasons Methylene blue (MB), the
oldest synthetic substance in medicine (1876 synthesized by BASF) is such a promising
candidate for an active treatment against SARS-CoV-2 infected people and for COVID-19
patients.