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Cognition

Methylene blue

Synthetic nootropic with weak human evidence for memory; historically used as a drug antidote and urinary antiseptic.

Methylene blue
35
score
C
evidence
Caution
risk

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Use with caution

This supplement may interact with medications, medical conditions or sensitive populations. Review safety before use.

Quick Take

Skip unless you are an experienced biohacker — evidence is thin and safety profile is messy.

Methylene blue is a synthetic phenothiazine dye with decades of clinical use as an antidote for methemoglobinemia and certain drug toxicities. It is not found in foods. Supplement interest stems from animal data suggesting mitochondrial and cognitive benefits. Small controlled human trials indicate that acute low-dose oral administration may improve memory retrieval and increase cerebral metabolic activity during tasks, but independent replication is lacking. It is primarily explored by self-experimenting adults interested in nootropics rather than as a nutritional corrective.

Potential benefits

01
May improve memory and attention
02
May prevent toxic encephalopathy

Protocol

Amount
0.5-2 mg
Frequency
Once daily, or only on high-demand cognitive days
When
Morning; avoid concurrent use with other serotonergic substances due to MAOI activity.

Onset Time

Acute cognitive effects within 1-2 hours; chronic benefits unknown.

Who Should Consider

Healthy adults seeking memory enhancement
Experienced nootropic self-experimenters
People under clinician care for drug-related encephalopathy

How It Works

At low concentrations, methylene blue crosses the blood-brain barrier and acts as a mitochondrial redox cycler, donating electrons to cytochrome c oxidase (complex IV) and potentially improving oxygen consumption. It also inhibits monoamine oxidase and guanylate cyclase, altering cerebral blood flow and neurotransmitter metabolism.

Updated 5/19/2026

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