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Methylene Blue

★ 70 FDA approved

Methylthioninium chloride

Mitochondrial electron donor and nootropic

Cognitive
Half-life
~5-6.5 hours in plasma; clearance extends over roughly a day via urine (blue-tinted)
Route
Oral
Cycle
No standardized cycling
Status
FDA-approved IV form for methemoglobinemia; small human fMRI trials support cognitive effects; oral nootropic use unregulated

About

A synthetic phenothiazine dye and small molecule (not a peptide) with over 130 years of medical use. FDA-approved as injectable ProvayBlue for acquired methemoglobinemia. At low oral doses it acts as an alternative electron carrier in the mitochondrial electron transport chain and a reversible MAO-A inhibitor, driving interest as a nootropic for attention, memory, and mitochondrial support. Sold as ready-to-use oral liquid drops; serotonin syndrome risk with antidepressants is the dominant safety concern.

Mechanism

Bypasses dysfunctional complexes I and III by donating electrons directly to cytochrome c oxidase, boosting mitochondrial ATP output. Inhibits monoamine oxidase A, raising serotonin and dopamine. At high doses paradoxically generates methemoglobin; at low doses reduces it.

Dosage

beginner

Amount
0.5-2 mg
Frequency
Once daily
Route
Oral (sublingual drops, with water or juice)
Duration
2-4 weeks

standard

Amount
5-20 mg
Frequency
Once daily
Route
Oral
Duration
4-12 weeks

advanced

Amount
0.5-4 mg/kg (research-context single doses up to 280 mg)
Frequency
Per study protocol
Route
Oral; IV reserved for clinical methemoglobinemia at 1 mg/kg
Duration
Acute or short-term only
Timing

Morning or early afternoon to avoid sleep disruption from mild stimulation. Take with food to reduce stomach upset. A 1% solution delivers ~0.5 mg per drop; a 2% solution ~1 mg per drop — verify concentration before dosing.

Cycle structure

No standardized cycling protocol exists for oral use. Cognitive studies used single acute doses. Common community pattern: 5-10 mg daily for 4-8 weeks, then 1-2 week break. Always assess MAO-inhibitor interactions before each cycle.

Reconstitution & Storage

N/A + N/A → N/A

Oral compound — no reconstitution needed.

Room temperature 15-30°C, away from direct light, cap tightly closed. Stains skin, fabric, and surfaces permanently — handle with care. Pharmaceutical-grade (USP) product only; industrial-grade contains heavy metals.

Benefits

  • • Improved sustained attention and short-term memory in fMRI studies
  • • Supports mitochondrial ATP synthesis via electron shuttle
  • • Mild mood elevation (MAO-A inhibition)
  • • Neuroprotective potential in preclinical models
  • • FDA-approved treatment for methemoglobinemia

Side effects

  • • Blue-green urine and stool (expected)
  • • Nausea, abdominal discomfort, headache
  • • Mild insomnia if dosed late
  • • Tongue and tooth staining (rinse mouth after sublingual use)
  • • Dizziness at higher doses

Contraindications

  • • G6PD deficiency (hemolysis risk)
  • • Pregnancy (fetal harm risk)
  • • Concurrent SSRIs, SNRIs, MAOIs, or other serotonergic drugs — serotonin syndrome emergency
  • • Severe renal impairment
  • • Breastfeeding (unknown safety)

Gender notes

Men

No sex-specific dosing adjustments.

Women

Hard contraindication in pregnancy. Discontinue at least 2 weeks before any serotonergic antidepressant initiation.

Research

Stacks well with

NAD-PLUS SEMAX CEREBROLYSIN

Track Methylene Blue doses in the app

Built-in reconstitution calculator, dose log, and reminders. Free on Android.

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Educational use only. Not medical advice. Many peptides shown are not FDA-approved and remain research compounds. Always consult a qualified healthcare provider.