Methylene Blue: Cognitive Enhancer or Overhyped Supplement?

Methylene blue is having a moment. It’s being hyped as a panacea for cognitive function, aging, and myriad other uses. Talk to patients about this ingredient.

So what is methylene blue? It’s a blue dye – made in a lab and used as a prescription drug for certain conditions like methemoglobinemia, a blood disorder. It’s also available as a supplement and is relatively new – with products such as drops and capsules increasingly promoted for “boosting mitochondrial health.”

What does the evidence say? In the brain, methylene blue is thought to donate electrons to the electron transport chain, promoting energy production and potentially boosting cognitive function. But clinical evidence is limited. Some research in patients with moderate Alzheimer disease shows that taking methylene blue modestly improves cognition compared to placebo, but this benefit appears to be dose-specific and is based on short-term studies. Clinical evidence on its use for cognitive function, memory, and aging in otherwise healthy adults is lacking.

As for safety, prescription methylene blue products have been used safely in both adults and children mostly when given intravenously short-term. While there isn’t any good safety data on supplemental forms of methylene blue, counsel patients that they might experience some common side effects, including changes in stool and urine color. As with many supplements, quality remains a concern, particularly as hype increases. Given the limited evidence of benefit and lack of safety data, advise patients to skip these products for now.

We’ll keep you informed as more data is available. Check out our new methylene blue monograph to learn more.