Comparison
Metformin vs Methylene Blue
Side-by-side of Metformin 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.
Metformin
Metformin for longevity: biguanide mechanism of action, TAME trial status, anti-aging dosage, weight loss data, life extension evidence in non-diabetics.
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
Metformin
- •Reduces HbA1c by ~1.0 to 1.5 percentage points in type 2 diabetes; first-line agent in major guidelines
- •DPP trial: 31% reduction in T2DM incidence in adults with prediabetes over 2.8 years
- •Suppresses hepatic gluconeogenesis via AMPK activation and complex I inhibition
- •Long-term use depletes B12; annual monitoring recommended after year 2
- •Lifespan extension in non-diabetic humans is not established; TAME trial pending
- •MASTERS trial reported blunted resistance-training hypertrophy in older adults
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 | Metformin | Methylene Blue |
|---|---|---|
| Category | pharmaceutical | pharmaceutical |
| Also known as | Glucophage, Fortamet, Glumetza, dimethylbiguanide | Methylthioninium chloride, Provayblue, tetramethylthionine chloride |
| Half-life (hr) ↗ | 6 | 5.5 |
| Typical dose (mg) ↗ | 1500 | 70 |
| Dosing frequency | 1 to 3 times daily with meals; XR once daily | 1 to 3 times daily for cognitive use; single IV dose for methemoglobinemia |
| Routes | oral | oral, intravenous |
| Onset (hr) | 1 | 1 |
| Peak (hr) | 2.5 | 1.5 |
| Molecular weight | 129.16 | 319.85 |
| Molecular formula | C4H11N5 | C16H18ClN3S |
| Mechanism | Suppresses hepatic gluconeogenesis primarily via AMPK activation and complex I inhibition; modestly improves peripheral insulin sensitivity and shifts gut microbiome composition. | 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 | Prescription only (FDA approved for type 2 diabetes 1994) | Prescription (injectable, FDA approved); supplement form (oral) widely available; not scheduled |
| WADA status | allowed | allowed |
| DEA / Rx | Rx only (not a controlled substance) | Not scheduled in the US |
| Pregnancy | Category B; used in gestational diabetes and PCOS per current guidance | Contraindicated |
| CAS | 657-24-9 | 61-73-4 |
| PubChem CID | 4091 | 6099 |
| Wikidata | Q19484 | Q409021 |
Safety profile
Metformin
Common side effects
- nausea
- diarrhea
- abdominal discomfort
- metallic taste
- decreased appetite
- B12 depletion (long-term)
Contraindications
- eGFR below 30 mL/min/1.73m2
- acute or chronic metabolic acidosis
- severe hepatic impairment
- acute heart failure
- iodinated contrast within 48 hours
Interactions
- iodinated contrast media: renal injury risk; hold 48 hours peri-imaging(major)
- alcohol (heavy use): elevated lactic acidosis risk(major)
- cimetidine: raises metformin plasma levels via OCT2 inhibition(moderate)
- insulin and sulfonylureas: additive hypoglycemia risk in combination(moderate)
- dolutegravir: raises metformin exposure via OCT2(moderate)
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?
Methylene Blue comes out ahead for most readers on the criteria we weight: 3 catalogued goals, controlled substance, oral dosing, with a Tier-A outcome catalogued. Metformin is the right call when one of the conditionals below applies.
- → If your priority is metabolic health and glucose control, pick Metformin.
- → If your priority is healthspan extension, pick Metformin.
- → If your priority is focus or working memory, pick Methylene Blue.
- → If your priority is mitochondrial function, pick Methylene Blue.
Edge case: Methylene Blue is contraindicated in pregnancy; Metformin is the safer pick if that applies.
Default choice: Methylene Blue. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Metformin 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 Metformin and Methylene Blue?
Metformin and Methylene Blue differ in category (pharmaceutical vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Metformin or Methylene Blue?
Metformin half-life is 6 hours; Methylene Blue half-life is 5.5 hours.
Can you stack Metformin 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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