Methylene Blue
A hospital drug with an FDA interaction warning, sold as a nootropic on one 26-person study.
D+
Evidence grade
D
Worth it
$10-20/month
Typical cost
DoseRead this before the number: methylene blue is a potent, reversible inhibitor of monoamine oxidase A. Combined with SSRIs, SNRIs, tramadol, linezolid, or other serotonergic drugs it can cause serotonin syndrome, which can be fatal; the FDA warned about exactly this combination in 2011. If you take any serotonergic medication, this substance is not a self-experiment. The studied acute dose was about 0.5 to 4 mg/kg in research settings using pharmaceutical-grade material; retail products range from aquarium and industrial grades (with heavy-metal contamination documented in technical-grade supply) to USP grade, and the label does not always tell you which you bought.
BasisMethylene blue is a real drug with real pharmacology, which is precisely why its supplement career grades badly.
Methylene blue is a century-old synthetic dye and drug: an approved intravenous treatment for methemoglobinemia, a laboratory stain, and a redox-active compound now marketed orally for cognition and mitochondrial support. We grade Methylene Blue D+ on evidence and D for worth-it at about $10-20 per month.
What it does
Methylene blue is a century-old synthetic dye and drug: an approved intravenous treatment for methemoglobinemia, a laboratory stain, and a redox-active compound now marketed orally for cognition and mitochondrial support. It is included here at the queue's direction and graded with its drug status in the foreground, because that status is what the marketing leaves out.
What the research says
One small study found a single low dose improved a memory task acutely; that is the healthy-human file
Evidence: weak. Rodriguez 2016 gave 26 healthy adults a single low dose or placebo and found improved performance on a memory retrieval task with corresponding brain-activity changes on fMRI. One study, 26 people, one dose, one task, never replicated at scale. In the longevity market this single pebble supports an edifice.
The Alzheimer's program built on it failed
Evidence: moderate. A stabilized methylene blue derivative (LMTM, TRx0237) was developed for Alzheimer's on tau-aggregation logic and failed its Phase 3 trials in 2016. Methylene blue itself is a genuinely approved drug for one thing, methemoglobinemia (a blood disorder), given intravenously in hospitals. Everything else in humans is investigation or anecdote.
Methylene blue is a real drug with real pharmacology, which is precisely why its supplement career grades badly. The benefit file for healthy users is one small unreplicated study and a failed Alzheimer's program. The risk file is institutional: an FDA warning about a potentially fatal interaction with common antidepressants, hemolysis risk in G6PD deficiency, and a retail supply chain where purity cannot be assumed. D+, and the grade is the least important sentence in this record.
Is it worth it?
Evidence (D+) sits far below the leaderboard floor, and the derived value at this price is D. About $15 a month. The grade does not price the interaction risk; the safety notes carry that. Derived from the October 2026 worth-it model.
Typical cost
$10-20/month
Common form, not a brand recommendation
Dosage context established
Read this before the number: methylene blue is a potent, reversible inhibitor of monoamine oxidase A. Combined with SSRIs, SNRIs, tramadol, linezolid, or other serotonergic drugs it can cause serotonin syndrome, which can be fatal; the FDA warned about exactly this combination in 2011. If you take any serotonergic medication, this substance is not a self-experiment. The studied acute dose was about 0.5 to 4 mg/kg in research settings using pharmaceutical-grade material; retail products range from aquarium and industrial grades (with heavy-metal contamination documented in technical-grade supply) to USP grade, and the label does not always tell you which you bought.
Worth-it leaderboard
Methylene Blue sits outside the worth-it top 20.
Methylene Blue sits outside the current top 20 on the gated leaderboard. The leaders below clear an evidence floor of B- before price counts at all, so cheap alone never earns a rank.
- 1AWorth itCreatine evidence A-~$5-10/mo
- 2AWorth itCaffeine evidence B+~$5-10/mo
- 3AWorth itVitamin D evidence B~$5-8/mo
See the full worth-it leaderboard →
When the evidence moves a grade, this ranking moves with it. Thursday is where you hear it first.
Safety notes
Serotonin syndrome with serotonergic medications is the headline risk and is stated in the dosage guidance because readers lift that section alone. Methylene blue can also cause hemolytic anemia in G6PD deficiency (a common inherited trait, often undiagnosed), turns urine and stool blue-green (harmless and alarming in that order), interferes with pulse-oximetry readings, and at high doses causes the very methemoglobinemia it treats at low doses. It stains everything it touches, including, metaphorically and literally, an emergency department's differential diagnosis if you arrive unwell: tell clinicians you take it.
Longevity Lab Report
Methylene Blue news. Graded when it happens.
The grade on this page stays free. The email carries the news on methylene blue: expert moves, dose changes, and what is working, in plain English every Thursday.
Changelog
Last updated 2026-10-23
- 2026-10-23|Graded with the extra care the queue assigned to this item: the record's center of gravity is the interaction profile, not the cognitive claim, because methylene blue is a potent MAO-A inhibitor being sold, largely without that warning, to an audience with high antidepressant use. Purity is treated as part of the grade: much of the retail supply is not pharmaceutical grade.
- 2026-10-23|Not listed under any goal: one unreplicated 26-person acute study does not carry a goal tag.
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This grade for Methylene Blue rests on the record above. When a new result changes that record, the grade changes with it, and the Thursday email is where the change lands first: the week's longevity and biohacking news, in plain English, linked back to the reasoning on this page.
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