Methylene Blue

Methylene blue, also known as methylthioninium chloride, is a salt used as a medication and dye. As a medication, it is mainly used to treat methemoglobinemia. Specifically, it is used to treat methemoglobin levels that are greater than 30% or in which there are symptoms despite oxygen therapy. It has previously been used for cyanide poisoning and urinary tract infections, but this use is no longer recommended. It is typically given by injection into a vein.