Comparison
Melatonin vs Methylene Blue
Side-by-side of Melatonin and Methylene Blue. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Melatonin
Melatonin as a sleep supplement: 0.3-1 mg matches physiological output, 3-10 mg is pharmacological. Shifts circadian phase, shortens sleep latency.
Methylene Blue
Methylene blue as a nootropic: low-dose cognitive enhancement, mitochondrial electron cycling, brain oxygen uptake, SSRI interaction risk, typical 0.5 to 4 mg.
Effects at a glance
Melatonin
- •Shortens sleep onset latency by ~7 to 12 minutes at physiological 0.3 to 1 mg doses
- •Advances circadian phase when taken 30 to 60 minutes before target bedtime, useful for jet lag and shift work
- •Does not meaningfully increase total sleep time in healthy adults without circadian misalignment
- •Endogenous nighttime production is not suppressed by short-term exogenous supplementation
- •Higher doses (3 to 10 mg) raise plasma levels above physiological range and often increase morning grogginess
- •Effective for delayed sleep-wake phase disorder and reducing jet-lag severity in eastward travel
Methylene Blue
- •FDA approved for methemoglobinemia and ifosfamide-induced encephalopathy
- •Mitochondrial electron-transport support at low doses (0.5 to 4 mg/kg) via cytochrome c shuttle
- •Potent MAO-A inhibitor; serotonin syndrome risk with SSRIs, SNRIs, MAOIs, fentanyl, tramadol, St John's wort
- •Causes harmless blue-green urine and sweat coloration; useful adherence marker
- •G6PD deficiency is an absolute contraindication; can trigger massive hemolysis
- •Cognitive-enhancement evidence is preliminary, mostly preclinical and small fMRI trials
Side-by-side
| Attribute | Melatonin | Methylene Blue |
|---|---|---|
| Category | supplement | pharmaceutical |
| Also known as | N-acetyl-5-methoxytryptamine | Methylthioninium chloride, Provayblue, tetramethylthionine chloride |
| Half-life (hr) ↗ | 0.75 | 5.5 |
| Typical dose (mg) ↗ | 0.5 | 70 |
| Dosing frequency | daily, 30 to 60 minutes before target sleep time | 1 to 3 times daily for cognitive use; single IV dose for methemoglobinemia |
| Routes | oral, sublingual | oral, intravenous |
| Onset (hr) | 0.5 | 1 |
| Peak (hr) | 1 | 1.5 |
| Molecular weight | 232.28 | 319.85 |
| Molecular formula | C13H16N2O2 | C16H18ClN3S |
| Mechanism | Agonist at MT1 and MT2 receptors in the suprachiasmatic nucleus, signaling biological night and promoting sleep-onset gating plus circadian phase shifts. | Mitochondrial electron carrier at low doses (cytochrome c shuttle to complex IV) and methemoglobin reductase substrate at higher doses; potent MAO-A inhibitor across the dose range. |
| Legal status | OTC in US; prescription in UK, EU, Japan | Prescription (injectable, FDA approved); supplement form (oral) widely available; not scheduled |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement in US; Rx in UK, EU, Japan, Australia | Not scheduled in the US |
| Pregnancy | Insufficient data; not routinely recommended | Contraindicated |
| CAS | 73-31-4 | 61-73-4 |
| PubChem CID | 896 | 6099 |
| Wikidata | Q179243 | Q409021 |
Safety profile
Melatonin
Common side effects
- vivid dreams
- morning grogginess (higher doses)
- headache
- dizziness
Contraindications
- autoimmune disease (theoretical)
- concurrent anticoagulant therapy without monitoring
Interactions
- fluvoxamine: CYP1A2 inhibition raises melatonin levels substantially(major)
- warfarin: possible increased bleeding risk(moderate)
- benzodiazepines and alcohol: additive sedation(moderate)
- antihypertensives: may alter blood pressure response(minor)
Methylene Blue
Common side effects
- blue-green urine and sweat
- skin and oral mucosa staining
- GI upset
- headache
- dizziness
Contraindications
- G6PD deficiency
- pregnancy
- concurrent serotonergic medication
- severe renal impairment
- infants under 6 months
Interactions
- SSRIs and SNRIs: serotonin syndrome, potentially fatal(major)
- MAOIs: additive MAO inhibition, serotonin syndrome risk(major)
- fentanyl, tramadol, meperidine: serotonin syndrome risk(major)
- dextromethorphan: serotonin syndrome risk(major)
- St John's wort: serotonin syndrome risk(major)
- lithium: additive serotonergic risk(major)
Which Should You Take?
Melatonin comes out ahead for most readers on the criteria we weight: 2 catalogued goals, OTC, oral dosing, with a Tier-A outcome catalogued. Methylene Blue is the right call when one of the conditionals below applies.
- → If your priority is sleep onset or sleep quality, pick Melatonin.
- → If your priority is circadian regulation, pick Melatonin.
- → If your priority is focus or working memory, pick Methylene Blue.
- → If your priority is mitochondrial function, pick Methylene Blue.
Edge case: If you want to avoid controlled substance, Melatonin is the more accessible choice.
Default choice: Melatonin. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Methylene Blue only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Melatonin and Methylene Blue?
Melatonin and Methylene Blue differ in category (supplement vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Melatonin or Methylene Blue?
Melatonin half-life is 0.75 hours; Methylene Blue half-life is 5.5 hours.
Can you stack Melatonin with Methylene Blue?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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