What is Methylene Blue?

Methylene blue is the parent molecule for hydroxychloroquine and chloroquine, off-patent drugs commonly used to treat not only malaria but also COVID-19. Best known as a fish tank antiseptic and textile dye for blue jeans, it was actually the first synthetic drug in modern history, developed in 1876. Since then, we’ve discovered it has many really important medicinal benefits.               

The first medical application of methylene blue was for malaria. In 1890, Paul Ehrlich, a scientist at the famous Charité Hospital in Berlin, Germany, discovered methylene blue inhibits an enzyme that weakens the malaria parasite.

One of the first antipsychotic medications was also made from methylene blue. Other drugs developed from or with it include antibiotics and antiseptics. In the past, it was commonly used to treat urinary tract infections. It’s also been used as an antiviral agent in blood used for transfusions.           

To this day, methylene blue is found in every hospital in the world, as it’s the only known antidote for metabolic poisons (any poison that interferes with oxygen transport or displaces oxygen, either from the blood or from the mitochondria).

For example, if you’re admitted for carbon monoxide poisoning, they’ll give you methylene blue intravenously. Cyanide is another example. The only known antidote for cyanide poisoning is methylene blue. It’s also been speculated that methylene blue might be useful in the treatment of acute lung infections such as SARS-CoV-2.