Peptides / Longevity and mitochondria

Small molecule · 319.9 Da

Methylene blue

ApprovedNot banned in sport

Methylene blue is an old dye and drug, approved as an injection for methemoglobinemia, a blood condition, with a boxed warning for serotonin syndrome. Some people take it by mouth for energy and focus, a use that is not approved or tested in trials. PepBank shows 210 results on methylene blue from 39 studies in people, and 12 from animal and lab studies. The strongest evidence is a randomized trial in people. Data as of 2026-10-30.

Also known as MB, C.I. 52015, Hydromethylthionine, NSC-215213, TRx0014, Basic Blue 9 and 12 more

Small molecule, shown without its saltPubChem 6099

Evidence level: Large trials in people210 of 222 results come from studies in people, including randomized trials.

Results in people

210

95% of 222 results

Results in animals

5% of 222 results

Results in lab cells

0% of 222 results

From computer models

0% of 222 results

Overview

Methylene blue at a glance

What it is	Small molecule
Approval	Approved in the US and EU (Methylthioninium chloride Proveblue, 2011)
In sport	Not listed as banned by WADA
Studies	44 studies with results. 39 of them gave methylene blue, with 222 results. 210 in people12 in animals
Best study in people	Randomized controlled trial with 598 people (2026)
Clinical trials	143 registered: 22 active or planned, 20 with posted results
Community use	Daily low-dose use for energy, alertness and mood; Clearer thinking, memory and focus (including 'brain fog'); Mitochondrial support, longevity and anti-aging claims; Situational use in low-oxygen settings, such as long flights or breath-hold swimming; Parkinson's-related symptoms and REM sleep behavior disorder (posts in a patient community); Colds, infections and urinary tract infections (individual comments)

The science

What is methylene blue?

Old blue phenothiazine dye and small-molecule drug. As the injection ProvayBlue it is approved for acquired methemoglobinemia, with a boxed warning for serotonin syndrome. Online communities also take low oral doses for energy and focus. That use is not approved and not tested in trials.

222

Study results in PepBank

The history of methylene blue

1892
The oldest paper on methylene blue in PepBank is from 1892.
2005June
A registered trial of methylene blue started (NCT00235183).
2011May
EMA approved Methylthioninium chloride Proveblue for acute symptomatic treatment of medicinal and chemical products-induced methaemoglobinaemia, in adults, children and adolescents (0 to 17 years). Hybrid medicine. Marketing authorisation holder Provepharm SAS.
2016April
FDA approved ProvayBlue for treatment of pediatric and adult patients with acquired methemoglobinemia. Dose: 1 mg/kg intravenously over 5 to 30 minutes, one repeat dose of 1 mg/kg after one hour if methemoglobin stays above 30 percent or symptoms persist. Boxed warning: serotonin syndrome with serotonergic drugs and opioids. Contraindicated in G6PD deficiency and severe hypersensitivity.
2020August
EMA approved Lumeblue for diagnostic agent that improves visualisation of colorectal lesions in adults who have screening or surveillance colonoscopy. Marketing authorisation holder Cosmo Technologies Ltd.

Methylene blue structure and chemistry

The key facts about the molecule. Long codes are in the closed section below.

Structure

Methylene blue is a small molecule, not a peptide chain.

Formula

C₁₆H₁₈ClN₃S

Molecular weight

319.9 g/mol

CAS number

61-73-4

Targets

Soluble guanylate cyclase (heterodimer of alpha and beta subunits) (gene GUCY1B1): inhibitorEvidence: ChEMBL mechanismAmine oxidase [flavin-containing] A (monoamine oxidase A) (gene MAOA): inhibitor (reversible; proposed)Evidence: approved-drug labelNADPH-dependent reduction of methemoglobin through leucomethylene blue: redox cycling (electron carrier)Evidence: approved-drug label

Development

Provepharm SAS (France) holds ProvayBlue (US) and Proveblue (EU); American Regent distributes the US label. Cosmo Technologies holds Lumeblue (oral, EU). TauRx develops the leuco form hydromethylthionine (LMTM) for Alzheimer disease (a different substance). Highest phase: past the trial stage (see status).

Identifiers

PubChem 6099, ChEMBL CHEMBL405110, UNII 8NAP7826UB, DrugBank DB09241, KEGG D02312

SMILES and InChIKey

InChIKey
CXKWCBBOMKCUKX-UHFFFAOYSA-M

SMILES
CN(C)C1=CC2=C(C=C1)N=C3C=CC(=[N+](C)C)C=C3S2.[Cl-]

See charge, composition and 3D structure on the Scientific page

The evidence

What methylene blue studies show

Results grouped by what the studies measured. Each card shows where its results come from.

Large trials in people210 of 222 results come from studies in people, including randomized trials.

Heart and blood vessels

76 results · 76 in people

In patients with septic shock, methylene blue prevented the stroke volume index from falling. Critical care medicine, 2001

Top results

In patients with septic shock, methylene blue prevented the stroke volume index from falling. (Critical care medicine, 2001)
In septic shock, methylene blue shortened time to stop vasopressors compared with placebo. (Critical care, 2023)
In patients with septic shock, methylene blue reduced lactate compared with before infusion, with a dose-dependent effect. (Nitric oxide, 2010)

Lungs and breathing

29 results · 26 in people · 3 animal

Oxygen delivery did not change significantly from baseline after methylene blue in patients with septic shock. Critical care medicine, 1995

Top results

Oxygen delivery did not change significantly from baseline after methylene blue in patients with septic shock. (Critical care medicine, 1995)
In septic shock, ventilation days were similar with methylene blue and placebo. (Critical care, 2023)
Oxygen consumption did not change significantly from baseline after methylene blue in patients with refractory septic shock. (Journal of critical care, 1998)

Survival and serious illness

21 results · 21 in people

In septic shock, death rates were similar with methylene blue and placebo. Critical care, 2023

Top results

In septic shock, death rates were similar with methylene blue and placebo. (Critical care, 2023)
In patients with septic shock, methylene blue reduced norepinephrine requirements by as much as 87% compared with controls. (Critical care medicine, 2001)
In septic shock, methylene blue shortened ICU stay by 1.5 days compared with placebo. (Critical care, 2023)

Mood, stress and behavior

8 results · 8 in people

In lamotrigine-treated bipolar patients, active-dose methylene blue improved Montgomery-Åsberg depression scores compared with low-dose methylene blue. The British journal of psychiatry, 2017

Top results

In lamotrigine-treated bipolar patients, active-dose methylene blue improved Montgomery-Åsberg depression scores compared with low-dose methylene blue. (The British journal of psychiatry, 2017)
Methylene blue slightly reduced mood ratings compared with placebo in bipolar patients and healthy controls. (BJPsych open, 2021)
Patients maintained on lithium were less depressed with methylene blue 300 mg/day than with 15 mg/day. (Biological psychiatry, 1986)

Memory and thinking

7 results · 7 in people

In Alzheimer's disease, no difference in cognitive scores was shown at 52 weeks, which the authors link to activity in the control arm. The journal of prevention of Alzheimer's disease, 2026

Top results

In Alzheimer's disease, no difference in cognitive scores was shown at 52 weeks, which the authors link to activity in the control arm. (The journal of prevention of Alzheimer's disease, 2026)
In patients with moderate Alzheimer's disease, methylthioninium improved cognitive scores compared with placebo. (Journal of Alzheimer's disease, 2015)
In lamotrigine-treated bipolar patients, methylene blue did not significantly change cognitive symptoms compared with the low-dose control. (The British journal of psychiatry, 2017)

Brain and nerves

5 results · 5 in people

In patients with mild Alzheimer's disease, methylthioninium benefited brain blood flow compared with placebo. Journal of Alzheimer's disease, 2015

Top results

In patients with mild Alzheimer's disease, methylthioninium benefited brain blood flow compared with placebo. (Journal of Alzheimer's disease, 2015)
Patients with ifosfamide-related brain depression recovered within 24, 48 or 72 hours with methylene blue, versus 48 hours in four untreated patients. (British journal of cancer, 2000)
Intravenous methylene blue rapidly reversed ifosfamide neurotoxicity in one patient. (Lancet, 1994)

All 44 methylene blue studies by area Open the Scientific page

Key methylene blue studies

Studies in people come first, then studies in animals and in the lab.

People
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
Wischik et al. 2026 · The journal of prevention of Alzheimer's disease · 598 people · cited by 6
2 results
People
Safety of the methylene blue plus chloroquine combination in the treatment of uncomplicated falciparum malaria in young children of Burkina Faso [ISRCTN27290841]
Meissner et al. 2005 · Malaria journal · 226 people · cited by 52
4 results
People
Efficacy and safety of triple combination therapy with artesunate-amodiaquine-methylene blue for falciparum malaria in children: a randomized controlled trial in Burkina Faso
Coulibaly et al. 2015 · The Journal of infectious diseases · 221 people · cited by 47
4 results
People
Early adjunctive methylene blue in patients with septic shock: a randomized controlled trial
Ibarra-Estrada et al. 2023 · Critical care (London, England) · 91 people · cited by 69
7 results
People
Efficacy and safety of primaquine and methylene blue for prevention of Plasmodium falciparum transmission in Mali: a phase 2, single-blind, randomised controlled trial
Dicko et al. 2018 · The Lancet. Infectious diseases · 40 people · cited by 88
2 results

All 44 Methylene blue studies

Methylene blue clinical trials

ClinicalTrials.gov lists 143 trials of methylene blue. 22 are active or planned, and 20 have posted results. PepBank does not show trial results.

Solid bars are dates that happened. Hatched bars are planned dates. Data from ClinicalTrials.gov.

The Safety and Efficacy of Methylene Blue MMX® Modified Release Tablets Administered to Subjects Undergoing Screening or Surveillance Colonoscopy

Phase 3completed1,249 people

Clinical and Microbiologic Outcomes of aPDT in the Non-surgical Treatment of Implant Inflammation

Phase 4completed56 people

Evaluation of Above the Cuff Suctioning During General Anesthesia

Phase 4terminated50 planned

All 30 Methylene blue trials

Status and safety

Is methylene blue approved?

FDA

United States

Approved

Methylene blue injection, generic (sponsors in Drugs@FDA: Zydus Lifesciences, Steriscience, Hikma, Meitheal, Nexus, Xiromed, Chengdu Shuode; DailyMed also shows injection labels from Amneal, Glenmark, Olic Thailand, BPI Labs and Zydus USA that are not in the application list read), ProvayBlue (methylene blue injection, USP, 5 mg/mL; 50 mg/10 mL and 10 mg/2 mL ampules and vials), since 2016.

EMA

European Union

Approved

Lumeblue (previously Methylthioninium chloride Cosmo) (oral delayed and extended release tablets), Methylthioninium chloride Proveblue (5 mg/mL solution for injection), since 2011.

WADA

Sport

Not banned

Not on the 2026 Prohibited List.

Yes. Approved in the US and EU (Methylthioninium chloride Proveblue, 2011). The EMA label for Methylthioninium chloride Proveblue says: “Acute symptomatic treatment of medicinal and chemical products-induced methaemoglobinaemia, in adults, children and adolescents (0 to 17 years)” Not listed as banned by WADA.

Laws and labels change, so check the regulator for the current status.

Methylene blue side effects and safety

PepBank has 48 safety results from studies of methylene blue. 43 of them come from studies in people.

Safety results from studies (48)

In children with malaria, adding methylene blue to chloroquine did not change serious adverse events compared with chloroquine alone. (Malaria journal, 2005)
In septic shock, death rates were similar with methylene blue and placebo. (Critical care, 2023)
In children with malaria, methylene blue plus AS-AQ lowered hemoglobin compared with AS-AQ. (The Journal of infectious diseases, 2015)
In patients with vasoplegia after cardiac surgery, morbidity and mortality were lower with methylene blue (0%) than with placebo (21.4%). (The Annals of thoracic surgery, 2004)
In male malaria participants, haemoglobin changes were similar with dihydroartemisinin-piperaquine plus methylene blue and dihydroartemisinin-piperaquine alone. (The Lancet. Infectious diseases, 2018)
In bipolar patients, methylene blue was well tolerated with temporary, mild side effects. (The British journal of psychiatry, 2017)
In patients with septic shock, methylene blue did not significantly affect white blood cells. (Critical care medicine, 2001)
In patients with septic shock, methylene blue increased the gastric-arterial carbon dioxide gap, and the increase depended on the dose. (Nitric oxide, 2010)
With methylene blue, 10/13 participants had mild or moderate infusion-site pain, which resolved within median 32.5 minutes. (BJPsych open, 2021)
Among patients receiving methylene blue for refractory vasoplegia after bypass, three died in hospital. (The Journal of thoracic and cardiovascular surgery, 2003)
No adverse effect was observed after methylene blue in patients with septic shock. (Critical care medicine, 1995)
No adverse effect was observed during methylene blue administration in patients with severe septic shock. (Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas, 1999)
All but one septic shock patient given methylene blue died. (Intensive care medicine, 1995)
In cardiac surgery patients with vasoplegia, methylene blue use was linked to higher hospital mortality than no methylene blue. (Journal of cardiothoracic and vascular anesthesia, 2013)
In post-bypass vasoplegia, early methylene blue administration was linked to fewer deaths than late administration. (The Annals of thoracic surgery, 2017)
No harmful side effects were reported after methylene blue in patients with septic shock. (Intensive care medicine, 1992)
In a patient with aniline poisoning, severe delayed red blood cell destruction followed methylene blue injections. (British journal of haematology, 1983)
In a boy with congenital methemoglobinemia, no treatment-related side effects were reported with prophylactic methylene blue. (Pediatric blood & cancer, 2016)
In children with malaria, adding methylene blue to chloroquine did not change other adverse events compared with chloroquine alone. (Malaria journal, 2005)
In children with malaria, haemoglobin did not differ significantly between chloroquine plus methylene blue and chloroquine alone. (Malaria journal, 2005)
In children with malaria, vomiting occurred more often with methylene blue plus AS-AQ than AS-AQ. (The Journal of infectious diseases, 2015)
In septic shock, no serious adverse effects were related to methylene blue. (Critical care, 2023)
In patients with septic shock, methylene blue did not significantly affect bilirubin. (Critical care medicine, 2001)
In patients with septic shock, methylene blue did not significantly affect the liver enzyme alanine aminotransferase. (Critical care medicine, 2001)

See every safety result on the Scientific page

Doses studied (31 shown)

The doses that these studies used. They are not recommendations.

Dose as reported	Class	Species	Route	Duration	Design	Source
4 mg twice weekly	Human	human	Not reported	52 weeks	Randomized trial in people · n = 598	Wischik 2026
12 mg/kg over three days	Human	human	Not reported	three days	Randomized trial in people · n = 226	Meissner 2005
15 mg/kg per day	Human	human	Not reported	3 days	Randomized trial in people · n = 23	Dicko 2018
138 mg/day	Human	human	Not reported	24 weeks	Randomized trial in people	Wischik 2015
2 mg/kg	Human	human	intravenous	Not reported	Randomized trial in people · n = 100	Ozal 2005
1.5 mg/Kg	Human	human	intravenous	Not reported	Randomized trial in people · n = 56	Levin 2004
195 mg	Human	human	Not reported	Not reported	Randomized trial in people · n = 37	Alda 2017
0.5 mg/kg	Human	human	intravenous	Not reported	Randomized trial in people · n = 30	Russo 2024
130 mg twice daily	Human	human	oral	3 days	Randomized trial in people · n = 24	Rengelshausen 2004
2 mg/kg bolus followed by 0.25, 0.5, 1, and 2 mg/kg/hr infusions	Human	human	intravenous	Not reported	Randomized trial in people · n = 20	Kirov 2001
50 mg	Human	human	intravenous	Single dose	Randomized trial in people · n = 16	Walter-Sack 2009
500 mg	Human	human	oral	Single dose	Randomized trial in people · n = 16	Walter-Sack 2009
500 mg oral and 50 mg intravenous	Human	human	oral and intravenous	Single dose	Randomized trial in people · n = 16	Walter-Sack 2009
1, 3 or 7 mg/kg	Human	human	infusion	20 min	Randomized trial in people · n = 15	Juffermans 2010
0.5mg/kg	Human	human	intravenous	Not reported	Randomized trial in people · n = 13	Sharp 2021
228 mg/day	Human	human	Not reported	Not reported	Randomized trial in people	Wischik 2015
2 mg/kg	Human	human	intravenous	20 minutes	Trial in people without random groups · n = 54	Leyh 2003
300 mg/day	Human	human	Not reported	1 year at 300 mg/day (2-year crossover trial)	Trial in people without random groups · n = 17	Naylor 1986
2 mg/kg	Human	human	intravenous	Short-term infusion	Trial in people without random groups · n = 14	Preiser 1995
1 mg/kg	Human	human	intravenous bolus	Not reported	Trial in people without random groups · n = 10	Andresen 1998
4 mg/kg	Human	human	intravenous	1-h infusion	Trial in people without random groups · n = 10	Weingartner 1999
2 mg/kg	Human	human	infusion	20-min infusion	Trial in people without random groups · n = 9	Daemen-Gubbels 1995
100 mg	Human	human	intravenous	Not reported	Trial in people without random groups · n = 7	Peter 2000
3 mg/kg of body weight	Human	human	intravenous	15-minute period	Trial in people without random groups · n = 7	Schenk 2000
3 mg kg(-1)	Human	human	intravenous	Not reported	Trial in people without random groups · n = 6	Gachot 1995
1.3 +/- 0.4 mg/kg	Human	human	Not reported	Not reported	Reports of single patients · n = 18	Kane 2007
6 x 50 mg day(-1)	Human	human	intravenous	Not reported	Reports of single patients · n = 12	Pelgrims 2000
4 x 50 mg day(-1)	Human	human	intravenous	Not reported	Reports of single patients · n = 3	Pelgrims 2000
2 mg.kg-1	Human	human	intravenous	Not reported	Reports of single patients · n = 2	Schneider 1992
50 mg	Human	human	intravenous	Not reported	Reports of single patients · n = 1	Küpfer 1994
2 milligrams/kilograms	Human	human	intravenous	Not reported	Reports of single patients · n = 1	Zygun 2005

From the community

How people use it

What people report online. It comes from forums and guides, not from studies.

Community-reported. Not tested in trials.

Sources report that people in biohacker and wellness groups take small oral doses of methylene blue, often about 10 to 20 mg a day as drops or powder in water, for energy, focus and mood. Some hold it in the mouth. The only approved use is a hospital injection for methemoglobinemia, and sources warn about serotonin syndrome with antidepressants.

Reported routines and cautions

What people use it for

Daily low-dose use for energy, alertness and moodS3 S5 S6S8S9
Clearer thinking, memory and focus (including 'brain fog')S3 S5S9S10
Mitochondrial support, longevity and anti-aging claimsS10 S11 S13
Situational use in low-oxygen settings, such as long flights or breath-hold swimmingS4 S5
Parkinson's-related symptoms and REM sleep behavior disorder (posts in a patient community)S6 S7
Colds, infections and urinary tract infections (individual comments)S5 S7

Reported regimens

Regimens that community sources report for Methylene blue. Community-reported, not tested in trials.
Context	Route	Amount	How often	How long	Agreement	Sources
Acquired methemoglobinemia, given by a clinician in hospital (US label of ProvayBlue, version of 2025-06-12). Not a community use.Official label dosing of an approved product	intravenous infusionover 5 to 30 minutes; the label says not to give it under the skin	1 mg/kg per dose	one dose; a repeat dose of 1 mg/kg may follow one hour later if methemoglobin stays above 30 percent or signs persist	up to 2 doses; the label says to consider other treatment if methemoglobinemia is not resolved after 2 doses	label	S1
Methemoglobinemia caused by drugs or chemicals, given by a healthcare professional (EU product Methylthioninium chloride Proveblue; EMA public summary).Official label dosing of an approved product	slow intravenous injectionover a period of five minutes	1 to 2 mg/kg per dose	one dose; a repeat dose may be given one hour after the first if symptoms persist or come back, or methemoglobin stays high	Not stated	label	S2
Daily low-dose use for energy, mood and clearer thinking (self-reported by people who take it)	oralliquid drops, or powder mixed in water; one forum poster mixes a measured amount in a glass of water	10 to 20 mg per day	daily or almost every day; often in the morning; some take one or two days off a week	one month to about 1.5 years in the posts	2 sources: 10 to 20 mg a day (S5, two comments) and about 10 mg a day (S6)	S5 S6
Daily use as capsules for thinking, energy and sleep, as told by a clinic doctor about patients	oralcapsule form	25 to 50 mg per day	daily	Not stated	single source	S3
Held or placed in the mouth (under the tongue, or as a lozenge) for mood, memory and energy	sublingual (drops under the tongue); a lozenge held in the mouth is also describedin the morning, before brushing the teeth; the lozenge (called a trouche) is held for about 30 minutes	10 mg per dose	once in the morning (one post)	Not stated	single source for the amount (a site with seller links); a second source describes the mouth-held lozenge without an amount	S9S13
Weight-based amounts named for liquid use	Not statedliquid (S3); the route is not stated in the S3 or S9 text	0.5 to 2 mg/kg per dose	Not stated	Not stated	2 sources name 0.5 mg/kg as a low figure; only one gives up to 2 mg/kg; one of them is a site with seller links	S3S9
Higher daily totals in forum posts, split over the day	oralliquid drops (S6 poster); the S7 poster does not state the route	10 to 15 mg per dose	two to four times a day (30 to 40 mg a day in total)	Not stated	sources differ: 10 mg four times a day (S7) and 15 mg twice a day (S6)	S6 S7
Very low amount in an on-off pattern, by a person who reports a mitochondrial condition	Not statedroute not stated in the comment	2 mg per day	3 days on, then 3 days off	Not stated	single source	S5
Situational use before a breath-hold swim and on flights with low cabin oxygen (a person told to the author)	Not statedroute not stated	30 mg per dose	taken earlier in the day before the swim; how often is not stated	Not stated	single source for the amount	S4 S5
Drops taken morning and bedtime for steady energy (user review)	oralliquid drops; the product strength is not stated, so the amount in mg is unknown	10 drops per dose	twice daily (morning and bedtime)	1 to 6 months (as the review page lists it)	single source	S8

Reported side effects

blue or blue-green urineS3 S6S9S10
blue stain on the tongue, mouth and teethS3S9S10 S11
headache or nausea, more often when taken late in the day; dizzinessS3 S11
serotonin syndrome when combined with antidepressants and other serotonergic drugsS1 S3 S10 S11
feeling angry all the time when doses build up without days off (one comment)S5
REM sleep behavior disorder got worse while taking 5 to 10 mg; the writer is not sure methylene blue is the cause (one forum post)S6
loss of effect after about 8 weeks, so the person pauses about 10 days (one review)S8

Reported benefits (claims, not shown in trials)

more energy, less fatigue, steadier energy through the work dayS3S8S9
clearer thinking or 'head is clearer'; better sleepS3 S5
better mood and memory (one nootropics post)S9
less involuntary movement and better smell, self-judged as 'all subjective' (one forum post)S6
longer breath-hold swimming and less fatigue on flights (one person, told by the author)S4

Cautions

The US label has a boxed warning: methylene blue may cause serious or fatal serotonin syndrome with serotonergic drugs and opioids. The label tells patients not to take serotonergic drugs within 72 hours after the last dose.S1
Articles list SSRIs, SNRIs, MAO inhibitors, linezolid, tramadol, dextromethorphan and methadone as drugs not to combine with methylene blue.S3 S11
The label lists G6PD deficiency (risk of hemolytic anemia) as a contraindication. A Substack author lists the same.S1 S4
Methylene blue in the blood can make a pulse oximeter read wrong.S1 S4
The label says methylene blue may cause fetal harm in pregnancy.S1
A scientist and professor quoted by National Geographic says people who take liquid drops can overdose easily, and that at extremely high doses methylene blue can itself cause methemoglobinemia.S11
A German pharmacists' portal says side effects can appear from about 2 mg/kg (nausea, vomiting, abdominal and chest pain).S12
A German pharmacists' portal says products bought from unsafe internet sources often lack chemical purity. A 2016 nootropics post says cheap dye versions contain toxic heavy metals. A forum poster bought a powder sold as 'USP grade'. Aquarium products carry the line 'Not for human consumption'. The page of an aquarium seller is a vendor page.S12S9S6
NPR quotes a scientist who strongly discourages taking methylene blue as a supplement because, he says, the risks outweigh the benefits.S10

Status notes

FDA approved methylene blue as ProvayBlue injection for acquired methemoglobinemia (label version 2025-06-12). Oral products for wellness are not approved.S1
NPR (2025-12-15) says it is not clear whether methylene blue meets the regulatory definition of a supplement, that FDA lists it as a generic drug that requires a prescription, and that most methylene blue products are not in the federal registry of dietary supplement labels.S10
A compounding pharmacy page says it makes methylene blue capsules under section 503A (its text names 2.5 mg and 5 mg as examples and its strength list runs from 2.5 mg to 100 mg), on prescription, and that no commercial oral methylene blue product is approved for general use. FDA's 503A page gives the conditions for bulk substances (USP or NF monograph, component of an approved drug, or the 503A list). The page does not mention methylene blue.S16
The EU authorises Methylthioninium chloride Proveblue as an injection for drug- or chemical-induced methemoglobinemia. Health Canada rejected the oral colonoscopy product Lumeblue on 2021-12-22. These are not wellness approvals.S2 S17

Community sources

S1PROVAYBLUE (methylene blue) injection, full prescribing information, American Regent, DailyMed version 28 (2025-06-12) (opens in a new tab)dailymed.nlm.nih.gov
S2Methylthioninium chloride Proveblue: EMA medicine page and EPAR public summary (opens in a new tab)ema.europa.eu
S3What Is Methylene Blue? The Viral Health Trend Raising Concerns (opens in a new tab)health.yahoo.com
S4Methylene Blue on the Airplane (Chris Masterjohn, PhD, Substack, 2025-04-13) (opens in a new tab)chrismasterjohnphd.substack.com
S5Comments on 'Methylene Blue on the Airplane' (Substack comment thread, April 2025) (opens in a new tab)chrismasterjohnphd.substack.com
S6One Month into Methylene Blue (Cure Parkinson's community, HealthUnlocked) (opens in a new tab)healthunlocked.com
S7Methylene Blue: Biohacker's Delight, or Playing with Fire? (Cure Parkinson's community thread, HealthUnlocked) (opens in a new tab)healthunlocked.com
S8Methylene blue user reviews and ratings (4 reviews)drugs.comcarries seller links, not linked
S9Nootropic: Methylene Blue - The Mood, Memory and Energy Enhancer (Adafruit Daily, 2016-09-27)adafruitdaily.comcarries seller links, not linked
S10What's behind the wellness claims for the synthetic dye methylene blue? (NPR, 2025-12-15) (opens in a new tab)npr.org
S11What is methylene blue and can it really boost your brain power? (National Geographic) (opens in a new tab)nationalgeographic.com
S12Methylenblau als Gehirn-Booster? Experten warnen vor Risiken (aponet.de, 2024-09-20, in German) (opens in a new tab)aponet.de
S13Methylene Blue: Nootropic nonsense (NZ Skeptics, 2022-03-14) (opens in a new tab)articles.skeptics.nz
S16Bulk drug substances used in compounding under section 503A of the FDCA (FDA, content current 2026-05-14) (opens in a new tab)fda.gov
S17Regulatory Decision Summary for Lumblue (Health Canada, decision 2021-12-22) (opens in a new tab)dhpp.hpfb-dgpsa.ca

plus 2 seller pages (not linked)

Gaps

Some forum posters report no benefit or that it did not agree with them (S6); they are not listed as effects. No Reddit (it can not be fetched). No Longecity or other biohacker forum thread could be opened by search; the forum material is two Parkinson's community threads, a Substack comment thread and four Drugs.com reviews, so amounts come from a few people. Amounts given in drops depend on product strength, which most posts do not state. Liposomal and sublingual products appear in only a few posts without amounts. No podcast transcript was read. No first-person report that names aquarium-grade product was found; the grade lines come from a pharmacists' portal, a nootropics post and one vendor label. Pharmaceutical-grade versus industrial dye is described, not tested. Drugs.com is marked affiliate because its page carries price and coupon links. Trial doses (for example in bipolar or Alzheimer studies) are in the literature and were not collected here.

Questions and more

Ask a question about methylene blue

The answer links to every study it uses.

What does the evidence say about methylene blue?Is methylene blue tested in people?Compare with NMN (nicotinamide mononucleotide)Compare with AICAR (acadesine)

Sources

Database: PepBank data for methylene blue (data version 308560)
Regulator: FDA status record
Regulator: EMA status record
Regulator: WADA status record
Trial registry: ClinicalTrials.gov
Community: community sources (forums and guides), as summarized in the PepBank community file

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

PepBank is a research reference. Talk to a doctor before you use any peptide.

Ask your AI about methylene blue

Methylene blue

ApprovedNot banned in sport

Also known as MB, C.I. 52015, Hydromethylthionine, NSC-215213, TRx0014, Basic Blue 9 and 12 more

What it is

Small molecule

Approval

Approved in the US and EU (Methylthioninium chloride Proveblue, 2011)

In sport

Not listed as banned by WADA

Studies

44 studies with results. 39 of them gave methylene blue, with 222 results.
210 in people12 in animals

Best study in people

Randomized controlled trial with 598 people (2026)

Clinical trials

143 registered: 22 active or planned, 20 with posted results

Community use

Daily low-dose use for energy, alertness and mood; Clearer thinking, memory and focus (including 'brain fog'); Mitochondrial support, longevity and anti-aging claims; Situational use in low-oxygen settings, such as long flights or breath-hold swimming; Parkinson's-related symptoms and REM sleep behavior disorder (posts in a patient community); Colds, infections and urinary tract infections (individual comments)

Dose as reported

Class

Species

Route

Duration

Design

Source

4 mg twice weekly

Human

human

Not reported

52 weeks

Randomized trial in people · n = 598

Wischik 2026

12 mg/kg over three days

Human

human

Not reported

three days

Randomized trial in people · n = 226

Meissner 2005

15 mg/kg per day

Human

human

Not reported

3 days

Randomized trial in people · n = 23

Dicko 2018

138 mg/day

Human

human

Not reported

24 weeks

Randomized trial in people

Wischik 2015

2 mg/kg

Human

human

intravenous

Not reported

Randomized trial in people · n = 100

Ozal 2005

1.5 mg/Kg

Human

human

intravenous

Not reported

Randomized trial in people · n = 56

Levin 2004

195 mg

Human

human

Not reported

Randomized trial in people · n = 37

Alda 2017

0.5 mg/kg

Human

human

intravenous

Not reported

Randomized trial in people · n = 30

Russo 2024

130 mg twice daily

Human

human

oral

3 days

Randomized trial in people · n = 24

Rengelshausen 2004

2 mg/kg bolus followed by 0.25, 0.5, 1, and 2 mg/kg/hr infusions

Human

human

intravenous

Not reported

Randomized trial in people · n = 20

Kirov 2001

50 mg

Human

human

intravenous

Single dose

Randomized trial in people · n = 16

Walter-Sack 2009

500 mg

Human

human

oral

Single dose

Randomized trial in people · n = 16

Walter-Sack 2009

500 mg oral and 50 mg intravenous

Human

human

oral and intravenous

Single dose

Randomized trial in people · n = 16

Walter-Sack 2009

1, 3 or 7 mg/kg

Human

human

infusion

20 min

Randomized trial in people · n = 15

Juffermans 2010

0.5mg/kg

Human

human

intravenous

Not reported

Randomized trial in people · n = 13

Sharp 2021

228 mg/day

Human

human

Not reported

Randomized trial in people

Wischik 2015

2 mg/kg

Human

human

intravenous

20 minutes

Trial in people without random groups · n = 54

Leyh 2003

300 mg/day

Human

human

Not reported

1 year at 300 mg/day (2-year crossover trial)

Trial in people without random groups · n = 17

Naylor 1986

2 mg/kg

Human

human

intravenous

Short-term infusion

Trial in people without random groups · n = 14

Preiser 1995

1 mg/kg

Human

human

intravenous bolus

Not reported

Trial in people without random groups · n = 10

Andresen 1998

4 mg/kg

Human

human

intravenous

1-h infusion

Trial in people without random groups · n = 10

Weingartner 1999

2 mg/kg

Human

human

infusion

20-min infusion

Trial in people without random groups · n = 9

Daemen-Gubbels 1995

100 mg

Human

human

intravenous

Not reported

Trial in people without random groups · n = 7

Peter 2000

3 mg/kg of body weight

Human

human

intravenous

15-minute period

Trial in people without random groups · n = 7

Schenk 2000

3 mg kg(-1)

Human

human

intravenous

Not reported

Trial in people without random groups · n = 6

Gachot 1995

1.3 +/- 0.4 mg/kg

Human

human

Not reported

Reports of single patients · n = 18

Kane 2007

6 x 50 mg day(-1)

Human

human

intravenous

Not reported

Reports of single patients · n = 12

Pelgrims 2000

4 x 50 mg day(-1)

Human

human

intravenous

Not reported

Reports of single patients · n = 3

Pelgrims 2000

2 mg.kg-1

Human

human

intravenous

Not reported

Reports of single patients · n = 2

Schneider 1992

50 mg

Human

human

intravenous

Not reported

Reports of single patients · n = 1

Küpfer 1994

2 milligrams/kilograms

Human

human

intravenous

Not reported

Reports of single patients · n = 1

Zygun 2005

Context

Route

Amount

How often

How long

Agreement

Sources

Acquired methemoglobinemia, given by a clinician in hospital (US label of ProvayBlue, version of 2025-06-12). Not a community use.Official label dosing of an approved product

intravenous infusionover 5 to 30 minutes; the label says not to give it under the skin

1 mg/kg per dose

one dose; a repeat dose of 1 mg/kg may follow one hour later if methemoglobin stays above 30 percent or signs persist

up to 2 doses; the label says to consider other treatment if methemoglobinemia is not resolved after 2 doses

label

Methemoglobinemia caused by drugs or chemicals, given by a healthcare professional (EU product Methylthioninium chloride Proveblue; EMA public summary).Official label dosing of an approved product

slow intravenous injectionover a period of five minutes

1 to 2 mg/kg per dose

one dose; a repeat dose may be given one hour after the first if symptoms persist or come back, or methemoglobin stays high

Not stated

label

Daily low-dose use for energy, mood and clearer thinking (self-reported by people who take it)

oralliquid drops, or powder mixed in water; one forum poster mixes a measured amount in a glass of water

10 to 20 mg per day

daily or almost every day; often in the morning; some take one or two days off a week

one month to about 1.5 years in the posts

2 sources: 10 to 20 mg a day (S5, two comments) and about 10 mg a day (S6)

S5 S6

Daily use as capsules for thinking, energy and sleep, as told by a clinic doctor about patients

oralcapsule form

25 to 50 mg per day

daily

Not stated

single source

Held or placed in the mouth (under the tongue, or as a lozenge) for mood, memory and energy

sublingual (drops under the tongue); a lozenge held in the mouth is also describedin the morning, before brushing the teeth; the lozenge (called a trouche) is held for about 30 minutes

10 mg per dose

once in the morning (one post)

Not stated

single source for the amount (a site with seller links); a second source describes the mouth-held lozenge without an amount

S9S13

Weight-based amounts named for liquid use

Not statedliquid (S3); the route is not stated in the S3 or S9 text

0.5 to 2 mg/kg per dose

Not stated

2 sources name 0.5 mg/kg as a low figure; only one gives up to 2 mg/kg; one of them is a site with seller links

S3S9

Higher daily totals in forum posts, split over the day

oralliquid drops (S6 poster); the S7 poster does not state the route

10 to 15 mg per dose

two to four times a day (30 to 40 mg a day in total)

Not stated

sources differ: 10 mg four times a day (S7) and 15 mg twice a day (S6)

S6 S7

Very low amount in an on-off pattern, by a person who reports a mitochondrial condition

Not statedroute not stated in the comment

2 mg per day

3 days on, then 3 days off

Not stated

single source

Situational use before a breath-hold swim and on flights with low cabin oxygen (a person told to the author)

Not statedroute not stated

30 mg per dose

taken earlier in the day before the swim; how often is not stated

Not stated

single source for the amount

S4 S5

Drops taken morning and bedtime for steady energy (user review)

oralliquid drops; the product strength is not stated, so the amount in mg is unknown

10 drops per dose

twice daily (morning and bedtime)

1 to 6 months (as the review page lists it)

single source

Methylene blue

Methylene blue at a glance

What is methylene blue?

The history of methylene blue

Methylene blue structure and chemistry

What methylene blue studies show

Heart and blood vessels

Lungs and breathing

Survival and serious illness

Mood, stress and behavior

Memory and thinking

Brain and nerves

Key methylene blue studies

Methylene blue clinical trials

Is methylene blue approved?

Methylene blue side effects and safety

How people use it

What people use it for

Reported regimens

Reported side effects

Reported benefits (claims, not shown in trials)

Cautions

Status notes

Community sources

Ask a question about methylene blue

Related peptides

Sources

Methylene blue

Methylene blue at a glance

What is methylene blue?

The history of methylene blue

Methylene blue structure and chemistry

What methylene blue studies show

Heart and blood vessels

Lungs and breathing

Survival and serious illness

Mood, stress and behavior

Memory and thinking

Brain and nerves

Key methylene blue studies

Methylene blue clinical trials

Is methylene blue approved?

Methylene blue side effects and safety

How people use it

What people use it for

Reported regimens

Reported side effects

Reported benefits (claims, not shown in trials)

Cautions

Status notes

Community sources

Ask a question about methylene blue

Related peptides

Sources