Methylene Blue
Methylene blue is a synthetic blue dye first made in the 19th century. It is used as a medicine for certain blood disorders and as a stain in laboratories.
What it is studied for
The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.
Why is a medical dye discussed for memory?
Methylene blue, also called methylthioninium chloride, is used medically to treat certain forms of methemoglobinemia, in which altered hemoglobin cannot carry oxygen effectively. Separately, researchers have explored brain effects, prompted partly by preclinical work on mitochondrial energy processing. The established medical use and the cognitive hypothesis are different questions. 1 2
Why people take it
SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.
Questions people ask
Is methylene blue an established memory supplement?
No. The cited human experiment is small and tests one dose; it does not establish sustained everyday benefits. 2
What is its established medical use?
The cited EU medicine treats methemoglobinemia caused by medicines or chemicals, helping restore effective oxygen transport. 1
Can it interact with antidepressants?
The FDA label warns of serious or fatal serotonin syndrome with serotonergic drugs, including SSRIs and SNRIs. 3
Why does G6PD deficiency matter?
The FDA label contraindicates the medicine in this condition because it can cause hemolytic anemia. 3