Prescription medicine / investigational nootropic

Methylene blue

Prepared by the ezGLP team. Sources last checked September 5, 2026.

Also known as Methylthioninium chloride

Routes represented in the knowledgebase: Oral / Other / unspecified.

Educational overview

FDA-approved only as an IV drug for acquired methemoglobinemia; oral wellness use is off-label. Major risks include serotonin syndrome and hemolysis in G6PD deficiency.

Category: Prescription medicine / investigational nootropic
Routes represented: Oral / Other / unspecified
Storage context: Protect from light; follow the dispensed product label.

Authoritative overview

Published literature

No validated PubMed or DOI link is currently curated for this entry.

Safety evidence

Common or reported: headache, nausea, diarrhea, low potassium or magnesium, myoclonus.

Serious or important: serotonin syndrome, hemolytic anemia, especially with G6PD deficiency, anaphylaxis, seizure-like effects.

The FDA label is for IV methylene blue; off-label oral wellness safety is not established.

Safety evidence source

Interaction evidence

These are general, pairwise evidence notes. Green identifies the potential-synergy category, while Lv3/Lv2/Lv1 communicates evidence strength; it does not guarantee benefit or cancel a safety warning.

With serotonergic medicines

Safety flag

Methylene blue inhibits monoamine oxidase and the combination can cause serious or fatal serotonin syndrome.

Interaction evidence source

Summarised from published literature for reference only, with citations to the source. Evidence is graded as reported and is not a recommendation to combine, dose, or use any compound.

For personal tracking and education only. Not medical advice, diagnosis, or treatment, and not a medical device. Peptides may be prescription-only or unapproved where you live — consult a licensed healthcare professional.