Methylene Blue
A century-old drug that can shuttle electrons in the mitochondrial energy chain; studied for memory and mitochondrial support. Dangerous with some antidepressants (serotonin syndrome).
FDA-approved as ProvayBlue for methemoglobinemia; other uses are off-label or experimental.
Look it up on Wikipedia3 listings across 2 independently tested vendors, ranked by price per milligram after coupon codes anyone can use. Vendors you can only order from by message are hidden.
Some links here are affiliate links: if you buy through one, this site may earn a commission at no extra cost to you. Prices, rankings and plans are worked out the same way whether or not a vendor pays one.
Daily price tracking started October 7, 2026; a price-history chart appears here once a few days have been collected.
| Vendor | Trust | Listing | Vials | Price | Per mg | |
|---|---|---|---|---|---|---|
Amino Usa #136 by metascore · US |
Metascore 74 medium confidenceFinnrick 32%Bought vials 89% of label · 3 testsTitrateLabNo report for thisAccount needed |
Methylene Blue 300mg | 1 × 300 mg | $20.00 | $0.067 | Buy |
Modern Aminos Affiliate #125 by metascore · US |
Metascore 75 medium confidenceFinnrick 79%PepIndex 81/100Bought vials 100% of label · 5 testsTitrateLab · PeptideBase · Peptide CriticNo report for thisOnline checkout |
Methylene Blue 10MG $30 off through this site's link (new customers) |
60 × 10 mg = 600 mg | $52.00 $30 off through this site's link (new customers) $0.87 per vial |
$0.087 | Buy |
Modern Aminos Affiliate #125 by metascore · US |
Metascore 75 medium confidenceFinnrick 79%PepIndex 81/100Bought vials 100% of label · 5 testsTitrateLab · PeptideBase · Peptide CriticNo report for thisOnline checkout |
Methylene Blue 5MG $30 off through this site's link (new customers) |
60 × 5 mg = 300 mg | $34.00 $30 off through this site's link (new customers) $0.57 per vial |
$0.113 | Buy |
Mixing a 10 mg vial
What each common amount of bacteriostatic water gives you on a U-100 insulin syringe. Pick a vial size above to change it.
| Water | Strength | Per 10 units (0.1 mL) | Per unit |
|---|---|---|---|
| 1 mL | 10 mg/mL | 1,000 mcg | 100 mcg |
| 2 mL | 5 mg/mL | 500 mcg | 50 mcg |
| 3 mL | 3.333 mg/mL | 333.3 mcg | 33.33 mcg |
| 5 mL | 2 mg/mL | 200 mcg | 20 mcg |
Doses studied in research Approved drug
What was given to people (or animals) in published studies and official labels, each linked to its source. This is not a recommendation: study products, purity and supervision differ from research-grade vials.
1 mg/kg intravenously over 5-30 minutes; a repeat dose of up to 1 mg/kg may be given one hour after the first if methemoglobin remains above 30% or symptoms persist; single dose of 1 mg/kg in moderate or severe renal impairment (intravenous)
Official label| Who was studied | Dose given | How often | For how long | What happened | |
|---|---|---|---|---|---|
| patients with bipolar disorder treated with lamotrigine (crossover) n = 37 |
195 mg (active) vs 15 mg (low-dose comparator) oral | daily | 6-month trial | depression and anxiety scores improved on the active dose; no significant effect on cognition | PubMed |
| patients with septic shock (pilot RCT) n = 20 |
2 mg/kg bolus, then 0.25, 0.5, 1 and 2 mg/kg/hr for 1 hour each intravenous | single bolus plus stepwise infusion | about 6 hours | raised mean arterial pressure and reduced vasopressor requirements vs saline | PubMed |
| patients with mild or moderate Alzheimer's disease; drug was LMTM, a reduced form of methylthioninium (phase 3) n = 891 |
75 mg or 125 mg LMTM (control 4 mg) oral | twice daily | 15 months | no benefit on cognition or daily function at either dose | PubMed |
| patients with MCI or mild-moderate Alzheimer's disease; drug was HMTM (hydromethylthionine) | HMTM 8 or 16 mg/day vs methylthioninium chloride 4 mg twice weekly as control oral | daily | 52 weeks, then all on 16 mg/day to 104 weeks | no separation on primary clinical endpoints at 52 weeks; later cognitive differences in the MCI subgroup | PubMed |
The approved use is intravenous treatment of methemoglobinemia. Methylene blue can cause serotonin syndrome with serotonergic drugs. LMTM/HMTM are related but distinct formulations.
What the research says
Human RCTs give mixed results: small studies found single low doses of methylene blue improved memory-task performance and that it eased residual depression in bipolar disorder, but large phase 3 Alzheimer's trials of the related compound LMTM/HMTM missed their primary endpoints. It can cause serotonin syndrome when combined with serotonergic antidepressants.
Key papers ✓ 2✗ 2~ 1? 2
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Efficacy and safety of tau-aggregation inhibitor therapy in patients with mild or moderate Alzheimer's disease: a randomised, controlled, double-blind, parallel-arm, phase 3 trial.Humans891 peopleRandomizedDouble-blind15 months (primary outcomes at week 65)Randomised, controlled, double-blind, parallel-group phase 3 trial of LMTM (a reduced methylthioninium form), 3:3:4
Phase 3 RCT (891 patients with mild-moderate Alzheimer's disease): LMTM, a reduced form of methylthioninium, showed no benefit on cognition or daily function over 15 months.
Key resultADAS-Cog vs control: 75 mg -0·02 (p=0·9834), 125 mg -0·43 (p=0·9323); ADCS-ADL: 75 mg -0·93 (p=0·8659), 125 mg -0·34 (p=0·9479)
Study details
- Studied
- Patients under 90 with mild to moderate Alzheimer's disease, 115 centres in 16 countries
- Compared with
- Control LMTM 4 mg twice daily (for blinding)
- Main outcome
- Change in ADAS-Cog and ADCS-ADL at week 65
- Sample
- 891 participants randomized (357 control, 268 LMTM 75 mg, 266 LMTM 125 mg)
- Authors' conclusion
- The primary analysis was negative and the results do not suggest benefit of LMTM as add-on treatment for mild to moderate Alzheimer's disease.
- Limitations
- Control arm received low-dose LMTM; many patients used other Alzheimer's medicines.
-
Clinical, imaging and blood biomarker outcomes in a Phase 3 clinical trial of tau aggregation inhibitor hydromethylthionine mesylate in mild cognitive impairment and mild to moderate dementia due to Alzheimer's disease.Humans598 peopleRandomized52 weeks controlled, followed to 104 weeksPhase 3 trial with modified delayed-start design; hydromethylthionine mesylate (HMTM) 16 or 8 mg/day
Phase 3 trial of HMTM (598 patients, MCI or mild-moderate Alzheimer's): no separation on primary clinical endpoints at 52 weeks, with later cognitive and biomarker differences in the MCI subgroup.
Key resultNo significant co-primary difference at 52 weeks; in MCI, ADAS-cog13 differences at 78 weeks (p = 0·0291) and 104 weeks (p = 0·0308); NfL progression reduced at 52 weeks (p = 0·0291)
Study details
- Studied
- Participants with MCI or mild to moderate dementia due to Alzheimer's disease, 82 centres
- Compared with
- Methylthioninium chloride 4 mg twice weekly (urinary colourant for blinding)
- Main outcome
- ADAS-cog11 and ADCS-ADL23; NfL, pTau217 and grey matter atrophy biomarkers
- Sample
- 598 amyloid β-PET positive participants (263 MCI, 335 mild to moderate dementia)
- Authors' conclusion
- Symptomatic activity in the control arm precluded separation on primary endpoints at 52 weeks; in MCI, clinical separation emerged only at 78 and 104 weeks. HMTM was well tolerated.
- Limitations
- Primary clinical endpoints not met at 52 weeks; control arm had symptomatic activity; later findings partly rely on external controls.
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Potential of Low Dose Leuco-Methylthioninium Bis(Hydromethanesulphonate) (LMTM) Monotherapy for Treatment of Mild Alzheimer's Disease: Cohort Analysis as Modified Primary Outcome in a Phase III Clinical Trial.Humans800 people18 monthsNon-randomized cohort analyses as modified primary outcomes within an 18-month phase III trial of LMTM
Revised, non-randomized cohort analysis of an 800-patient phase 3 LMTM trial suggested benefit for monotherapy users; authors state a new randomized trial is needed.
Study details
- Studied
- Patients with mild Alzheimer's disease
- Compared with
- LMTM 4 mg twice a day (randomized control, add-on or monotherapy)
- Main outcome
- ADAS-cog, ADCS-ADL, MRI atrophy, glucose uptake
- Sample
- 800 mild AD patients randomized; monotherapy subgroups n = 79 and n = 76
- Authors' conclusion
- Results support the hypothesis that LMTM might be effective as monotherapy and that 4 mg twice a day may work as well as higher doses; a further randomized trial is required.
- Limitations
- Primary analysis revised before unblinding to non-randomized subgroup comparisons; monotherapy vs add-on is not randomized.
-
Methylene blue treatment for residual symptoms of bipolar disorder: randomised crossover study.HumansThirty-seven participants enrolledRandomizedPlacebo-controlledDouble-blind6 monthsDouble-blind randomised crossover study
Crossover RCT in 37 people with bipolar disorder: methylene blue improved residual depression and anxiety scores, but not cognition.
Key resultActive dose 195 mg improved depression on MADRS and HAM-D (P = 0.02 and 0.05) and anxiety on HAM-A (P = 0.02)
Study details
- Studied
- Patients with bipolar disorder treated with lamotrigine
- Compared with
- Low dose methylene blue 15 mg ('placebo')
- Main outcome
- Depression, mania, anxiety and cognitive functioning
- Authors' conclusion
- Methylene blue as adjunct improved residual depression and anxiety symptoms in bipolar disorder; effects on cognition were not significant.
- Limitations
- Comparator was a low active dose rather than inert placebo; small sample.
-
Multimodal Randomized Functional MR Imaging of the Effects of Methylene Blue in the Human Brain.Humanssize not reportedRandomizedPlacebo-controlledDouble-blindSingle dose; imaging 1 hour after administrationProspective randomized, double-blinded, placebo-controlled fMRI trial; single low oral dose
RCT in 26 healthy adults: a single low dose of methylene blue increased brain fMRI responses and improved correct memory-retrieval answers by 7% versus placebo.
Key result7% increase in correct responses during memory retrieval (P = .01)
Study details
- Studied
- Healthy adults
- Compared with
- Placebo
- Main outcome
- fMRI activity during sustained attention and short-term memory tasks
- Sample
- Twenty-six healthy subjects enrolled (age 22-62)
- Authors' conclusion
- Low-dose methylene blue can increase functional MR imaging activity during sustained attention and short-term memory tasks and enhance memory retrieval.
- Limitations
- Healthy volunteers, single dose, small sample.
-
Methylene blue modulates functional connectivity in the human brain.Humanssize not reportedRandomizedPlacebo-controlledDouble-blindSingle dose; imaging 1 hour after administrationRandomized, double-blinded, placebo-controlled task-based and task-free fMRI; single low oral dose
Placebo-controlled fMRI study in healthy adults: a single low dose altered brain network connectivity; no clinical outcomes were measured.
Study details
- Studied
- Healthy adults
- Compared with
- Placebo
- Main outcome
- Cerebral blood flow and functional connectivity
- Authors' conclusion
- Low-dose methylene blue modulated task-related and resting-state neural networks, supporting further investigation in healthy and disease populations.
- Limitations
- Single dose in healthy adults; sample size not given in abstract.
-
The role of methylene blue in serotonin syndrome: a systematic review.Humans26 peopleSystematic review of case reports and clinical audits
Review of 9 case reports and 2 audits: 26 patients developed acute confusion after IV methylene blue, 25 of whom were on serotonergic drugs, consistent with serotonin syndrome.
Study details
- Studied
- Patients who received methylene blue and developed confusion, neuropsychiatric complications or autonomic instability (24 were taking an SRI)
- Main outcome
- Serotonin syndrome after methylene blue
- Sample
- 9 case reports and 2 retrospective reviews; 26 patients developed an acute confusional state
- Authors' conclusion
- Serotonin reuptake inhibitors can interact with methylene blue, causing a serious adverse reaction consistent with serotonin syndrome.
- Limitations
- Based on case reports and retrospective reviews.
Reported side effects
- commonGastrointestinal effects [ref]
- commonUrinary effects [ref]
- commonDose-dependent decrease in hemoglobin [ref]
- uncommonHeadache [ref]
- uncommonDiarrhea [ref]
- reportedSerotonin syndrome when combined with serotonergic antidepressants [ref]
Serious serotonin toxicity has been reported when methylene blue is given to people taking SSRIs or similar drugs.
128 registered human trials (22 active)
✓ positive · ✗ negative · ~ mixed · ? inconclusive, judged on each paper's own main outcome. Grades: A strong human evidence → D little or none. Papers and verdicts are drawn from PubMed, Europe PMC and Russian journals (CyberLeninka); not medical advice.
Registered clinical trials 128 on ClinicalTrials.gov · 22 active · 71 completed · 19 with posted results
All 128 Methylene Blue trials, with countries and summaries · Search ClinicalTrials.gov · Recruiting trials for every peptide
Discussions elsewhere
Experiences and questions about Methylene Blue on other sites. Treat anecdotes with care.
Also sold in blends with Methylene Blue
Methylene Blue + NAD+ (1). The order planner uses these automatically when a blend is cheaper than separate vials.
Methylene Blue: questions people ask
What is Methylene Blue?
Redox dye (not a peptide). A century-old drug that can shuttle electrons in the mitochondrial energy chain; studied for memory and mitochondrial support. Dangerous with some antidepressants (serotonin syndrome). Also searched as methylene.
How much does Methylene Blue cost?
The cheapest Methylene Blue from an independently tested vendor is $0.067 per mg (Amino Usa, Methylene Blue 300mg, $20.00). Across 3 listings from 2 vendors the median is $0.087 per mg.
Where can I buy Methylene Blue?
2 vendors tested by Finnrick sell Methylene Blue. The cheapest per mg right now: Amino Usa ($0.067), Modern Aminos ($0.087). 0 of them publish a lab report (COA) for Methylene Blue; compare lab scores and reports in the table above before buying.
Is Methylene Blue FDA approved?
FDA-approved as ProvayBlue for methemoglobinemia; other uses are off-label or experimental.
Does Methylene Blue work? What does the research say?
Evidence grade B (some human evidence), from 7 papers: Only small RCTs of methylene blue itself (memory, bipolar depression); the large Alzheimer's trials used the related LMTM/HMTM and missed their goals. Human RCTs give mixed results: small studies found single low doses of methylene blue improved memory-task performance and that it eased residual depression in bipolar disorder, but large phase 3 Alzheimer's trials of the related compound LMTM/HMTM missed their primary endpoints. It can cause serotonin syndrome when combined with serotonergic antidepressants. See the papers.
Are there clinical trials of Methylene Blue?
ClinicalTrials.gov lists 128 registered trials of Methylene Blue: 22 active, 71 completed, 18 in phase 3, 19 with posted results. Examples: Efficacy of Methylene Blue Plus Ropivacaine for Post-Hemorrhoidectomy Pain. (Not yet recruiting, Phase 4, 177 people); Intravenous Methylene Blue for Treating Refractory Neonatal Septic Shock (Not yet recruiting, Phase 2, Phase 3, 130 people); Efficacy of Methylene Blue Photodynamic Therapy for Treatment of Deep Tissue Abscesses (Not yet recruiting, Phase 2, 120 people).
What dose of Methylene Blue was used in studies?
Methylene Blue is an approved drug. ProvayBlue: 1 mg/kg intravenously over 5-30 minutes; a repeat dose of up to 1 mg/kg may be given one hour after the first if methemoglobin remains above 30% or symptoms persist; single dose of 1 mg/kg in moderate or severe renal impairment; patients with bipolar disorder treated with lamotrigine (crossover): 195 mg (active) vs 15 mg (low-dose comparator) daily; patients with septic shock (pilot RCT): 2 mg/kg bolus, then 0.25, 0.5, 1 and 2 mg/kg/hr for 1 hour each single bolus plus stepwise infusion. These are amounts used in published studies or official labels, not a recommendation.
What are the side effects of Methylene Blue?
Reported in the research: Gastrointestinal effects; Urinary effects; Dose-dependent decrease in hemoglobin; Headache; Diarrhea. Serious serotonin toxicity has been reported when methylene blue is given to people taking SSRIs or similar drugs.
Where do people discuss Methylene Blue? Is there a Methylene Blue Reddit?
Communities focused on it include r/methylene_blue. Experiences shared there aren't evidence, and some allow vendor promotion. All communities.