Comparison
Methylene Blue vs NMN
Side-by-side of Methylene Blue and NMN. 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.
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.
NMN
NMN supplements are oral nicotinamide mononucleotide capsules sold for longevity, energy, and metabolic health. They raise plasma NAD+ 30-90% at 250-1000.
Effects at a glance
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
NMN
- •Plasma NAD+ rises 30-90% at 250-1000 mg/day across human PK studies
- •Tissue NAD+ rise is inconsistent across human trials (Yoshino 2021, Igarashi 2022)
- •No human trials measure hard endpoints (mortality, CV events, cancer); evidence is biomarker-only
- •Most trials cluster at 250-500 mg/day; dose-response above 250 mg/day is poorly characterized
- •FDA position contested; widely sold as supplement but with regulatory uncertainty
- •Marketing claims for fertility and longevity outrun the human trial evidence substantially
Side-by-side
| Attribute | Methylene Blue | NMN |
|---|---|---|
| Category | pharmaceutical | supplement |
| Also known as | Methylthioninium chloride, Provayblue, tetramethylthionine chloride | nicotinamide mononucleotide, beta-NMN |
| Half-life (hr) ↗ | 5.5 | 4 |
| Typical dose (mg) ↗ | 70 | 250 |
| Dosing frequency | 1 to 3 times daily for cognitive use; single IV dose for methemoglobinemia | 1x daily, often morning |
| Routes | oral, intravenous | oral, sublingual |
| Onset (hr) | 1 | 1 |
| Peak (hr) | 1.5 | 3 |
| Molecular weight | 319.85 | 334.22 |
| Molecular formula | C16H18ClN3S | C11H15N2O8P |
| Mechanism | 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. | Direct precursor in the NAD+ salvage pathway; converted to NAD+ by NMNAT enzymes in essentially every tissue. Raised NAD+ supports sirtuin and PARP enzyme activity. |
| Legal status | Prescription (injectable, FDA approved); supplement form (oral) widely available; not scheduled | Contested in US (FDA position 2022); widely sold as supplement; broadly available in EU, UK, Asia |
| WADA status | allowed | allowed |
| DEA / Rx | Not scheduled in the US | Not scheduled |
| Pregnancy | Contraindicated | Insufficient data; precautionary avoidance |
| CAS | 61-73-4 | 1094-61-7 |
| PubChem CID | 6099 | 14180 |
| Wikidata | Q409021 | Q418972 |
Safety profile
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)
NMN
Common side effects
- mild GI upset (rare)
- occasional headache
- flushing (rare)
Contraindications
- pregnancy and lactation (precautionary, no data)
- active cancer (theoretical concern, not evidence-based)
Interactions
- metformin: no clinically significant interaction documented; both modulate metabolism through different mechanisms(minor)
- chemotherapy agents: theoretical concern about supporting cancer cell proliferation; coordinate with oncology team(moderate)
- CD38 inhibitors: would amplify NMN-induced NAD+ rise; not clinically relevant for most users(minor)
Which Should You Take?
NMN comes out ahead for most readers on the criteria we weight: 3 catalogued goals, Contested in US (FDA position 2022); widely sold as supplement; broadly available in EU, UK, Asia, 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 focus or working memory, pick Methylene Blue.
- → If your priority is mitochondrial function, pick Methylene Blue.
- → If your priority is healthspan extension, pick NMN.
- → If your priority is energy and stamina, pick NMN.
Edge case: Methylene Blue is contraindicated in pregnancy; NMN is the safer pick if that applies.
Default choice: NMN. 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 Methylene Blue and NMN?
Methylene Blue and NMN differ in category (pharmaceutical vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Methylene Blue or NMN?
Methylene Blue half-life is 5.5 hours; NMN half-life is 4 hours.
Can you stack Methylene Blue with NMN?
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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