Methylene Blue for Cancer: What You Need to Know (2026)
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. Methylene blue is approved by the Food and Drug Administration (FDA) as a treatment for methemoglobinemia, a condition that strips hemoglobin of its ability to carry oxygen throughout the body. When this occurs, the body's tissues are deprived of oxygen, resulting in tissue death. Methylene blue helps reverse this condition through a series of steps that res...