Approved drug — used here for education. This is an approved/prescription medicine in at least one region; "research"/compounded versions sold as chemicals are a separate, riskier thing. Not medical advice.
What it is
Methylene blue is a synthetic dye (not a peptide) and one of the oldest drugs — FDA-approved to treat methemoglobinemia, and studied at low doses for mitochondrial/cognitive effects.
Proposed mechanism
At low doses it acts as an alternative electron carrier in the mitochondrial electron-transport chain and has antioxidant/redox effects; it is also a potent MAO inhibitor (a key drug-interaction caution).1
State of the evidence
Approved for methemoglobinemia; cognitive/longevity uses are emerging/unproven.
Regulatory & status
FDA-approved for a specific indication; other uses off-label. Serotonergic drug interactions are dangerous.
For educational and research purposes only. This content is not medical advice. Methylene blue is a drug with serious interactions; use only under a licensed professional. Free Peptide University does not sell compounds.