Dear Editor, I would like to comment on the article "COVID-19 should be a methylene blue "promoter"^[1]". Evora noted that "I decided to resubmit the letter now, considering that COVID-19 should be a methylene blue 'promoter', and the dye can get the lifesaving status it deserves ^[1]." In fact, the use of classic available agent as a possible therapeutic agent for the emerging COVID-19 should be supported. It is better than do nothing. Many classic drugs such as hydroxychloroquine are proposed and tested for managing COVID-19^[2]. At the moment, we have to take the risk of a new alternative proposal for the treatment of COVID-19 such as convalescent plasma therapy^[3]. Using a safe and well-known agent might not have a confirmation for its efficacy but we have many data on its safety, and it might be a good alternative option compared to a totally unknown new alternative.